Hi guys,
I'm using activities a lot, 13 activities and growing, usually, there are a few firefox windows on each activity, as I work mostly online.

I have an issue with the windows (firefox or otherwise) kind of randomly switching activities every time I restart the computer, some stay in the activity where I put them, some just go to a different activity.

I have no idea what's going on but... Maybe when I add a new activity the activity ID (or order of activities) changes but the windows still have the old activity ID/order and that's why they appear on the wrong activity?

I understand entirely, having basically the same configuration as you and having been experiencing the same problems for a long time; even going back to Plasma 4. From my experience, sometimes it does just work (primarily if I'd done a clean logout) and sometimes it doesn't (most of the time when I'm starting firefox after things crashed). I've just always dealt with it, chalking it up as firefox not entirely cooperating with plasma activities. I'm doubtful the activity ids are getting scrambled as those are set once and saved in various config files (~/.config/plasma*, ~/.config/kactivitymanagerd*); I think it's probably more that firefox (and/or plasma) is getting mixed up somewhere along the way and failing to reassign its windows correctly.

That said, there may be a way to solve the problem, so it may be worthwhile submitting a case to get it fixed.

Thanks for sharing your experience @airdrik.

airdrik wrote: sometimes it does just work and sometimes it doesn't
I think it's probably more that firefox (and/or plasma) is getting mixed up somewhere along the way and failing to reassign its windows correctly.

That said, there may be a way to solve the problem, so it may be worthwhile submitting a case to get it fixed.

It's really frustrating, for me activities are the key differentiator of KDE Neon and this issue makes me have to re-assign all my windows, (several dozens usually) after each reboot, crash, etc (and sadly my system is not that stable, so that's at least twice a week), if you have a crash in the middle of a work session, it gets very infuriating!

I'm trying to identify what happens and when, maybe after I find out that I can submit a case, but as of now it seems kind of random...
Where do you think it would be the right place to post once I have more data?
How can I start tracking the issue in a more scientific way? Logs?

I think it's probably more that firefox (and/or plasma) is getting mixed up somewhere along the way and failing to reassign its windows correctly.

I am now testing a theory, one window will "pertain" to the activity it was created on, no matter how much you move it around, the problem gets more complicated when you start moving tabs from one window to another... Will report back if I find any consistent behavior that we can then use to submit a case.

Before firefox I had been using Chromium, that was much worst, it was completely unaware of activities, is there maybe some other browser that's better integrated with KDE Neon/Plasma?

OK, I've just found out that KDE-Firefox integration is a 18-year-old problem that is still yet to be fully solved...

Findings:
As I suspected, windows belong to the activity they were initially created. So there's that... we might want to lower our expectations if we want to keep it working.

I've also found something pretty interesting:
https://github.com/jasonmoofang/activityfox
Check it out!

Also, there's an issue with decorations, firefox and Activities, so maybe our issue is because of that. Hence, if you have the "Plasma-firefox" plugin installed (as I did) you might want to disable it, it might solve the problem for you.

And finally, before I start patching my system with some 7 year old code... I will just try to see If I can be friends with "Konqueror" (I'm guessing it works well with activities this one...). This is going to be my first move, because I havent really given it a try yet and because it's the simpler option XD.

I will also try to "hibernate" (stop) activities and reboot, see if that makes a change.

More findings from the Internets:

- Firefox has "containers" to separate tasks on Web? I.e. work, hobby etc.
- In neon, you can use different Firefox profiles in different Activities, launching them with different .desktop files associated to each Activity.
- Some more FF+KDE tinkering found here: https://bbs.archlinux.org/viewtopic.php?id=137941

yosucadilla wrote:Where do you think it would be the right place to post once I have more data?

I would recommend posting the resulting bug report at bugs.kde.org. If it turns out the problem is entirely in Firefox, it can be escalated from there.

yosucadilla wrote:OK, I've just found out that KDE-Firefox integration is a 18-year-old problem that is still yet to be fully solved...

Findings:
As I suspected, windows belong to the activity they were initially created. So there's that... we might want to lower our expectations if we want to keep it working.

I've also found something pretty interesting:
https://github.com/jasonmoofang/activityfox
Check it out!

I think I'd seen that before. I would have skipped over it as from my experience the firefox activity associations have worked well enough. (granted my systems seem to have been generally more stable than what I've seen people experience with Neon; and it seems that when the system/firefox is able to shut down cleanly then it will come up cleanly in the state I'd left it).

yosucadilla wrote:
Also, there's an issue with decorations, firefox and Activities, so maybe our issue is because of that. Hence, if you have the "Plasma-firefox" plugin installed (as I did) you might want to disable it, it might solve the problem for you.

My general recommendation here is to turn off browsers' client-side decorations and use the system decorations. Not just for consistency with the rest of the system but also because there are certain things that Kwin can't handle with windows that provide their own decorations, such as activity associations.
I thought I may have had a firefox-plasma plugin, package or something installed, but apparently I only have one for kwallet integration.

yosucadilla wrote:
And finally, before I start patching my system with some 7 year old code... I will just try to see If I can be friends with "Konqueror" (I'm guessing it works well with activities this one...). This is going to be my first move, because I havent really given it a try yet and because it's the simpler option XD.

You might also give Falkon a try which is a recent addition to the KDE collection of applications (though I don't think it's released as part of the KDE Applications suite (yet?)).

Likely you'll get a similar look-and-feel to the sites as they both use the same QtWebEngine for rendering. The main difference is that Konqueror is a container for various view components, which includes a web browser as well as a file browser, a text editor, a document viewer, etc.; while Falkon is a dedicated web browser app.

yosucadilla wrote:
I will also try to "hibernate" (stop) activities and reboot, see if that makes a change.

My experience with that has been that it doesn't close the (firefox) browser windows that were open on those activities (as I would have hoped). It just hides them, with the possibility that they could be pulled up on another Activity, or if you log out and in with the Activity in that state then it will pull up the window on whatever Activity you are on when you log in.

yosucadilla wrote:
More findings from the Internets:

- Firefox has "containers" to separate tasks on Web? I.e. work, hobby etc.

These containers are mostly for separating the memory use and processing of distinct web sites, and is largely orthogonal to the windows and tabs you have open (unless they made that a hard separation)

yosucadilla wrote:- In neon, you can use different Firefox profiles in different Activities, launching them with different .desktop files associated to each Activity.

That may be worthwhile if you want that level of separation between the windows assigned to each Activity. I'm skeptical if it would be in my case as I use a lot of the same sites (internal work-related) on multiple Activities and want the shared profile.

yosucadilla wrote:- Some more FF+KDE tinkering found here: https://bbs.archlinux.org/viewtopic.php?id=137941

There's also been a lengthy discussion in these forums about it: viewtopic.php?f=14&t=17786. You can probably skip to the last page or two to find the most recent information; I believe most of the kinks discussed have been resolved upstream.