After upgrading KDE to 5.23.3, I see that the device notifier popup (now apparently called "disk and devices"?) changed the action button to "Mount and Open" instead of the previous "Mount" (no automatic opening). I don't use this lame Dolphin or any other graphical "file manager", so the "...and open" part opens a useless window for me. I would prefer this to only mount the device.

Is there any way to restore the previous behavior? Is it configurable? There is nothing in the settings that I could find about this.

If you click that "down arrow" to the right of "mount and open", it should open a drop down, and one of the options there should be to just mount the device.

As another option, you may be able to control what is launched when a device is opened, under System setting->Applications->File associations. I assume the entry for a directory controls this, so if you search for "directory" there, and select that, you should see the list of applications for a directory. You should be able to change the first entry there from Dolphin to something else, such as a terminal, or (maybe) remove everything from that list so that the "open" action does nothing.

Section_8 wrote:If you click that "down arrow" to the right of "mount and open", it should open a drop down, and one of the options there should be to just mount the device.

Yes, thank you, that is what I ended up doing. Interestingly, I did try to click that arrow before posting in the forum, and it did nothing at that attempt, so I thought that it was there to change the sorting order of devices, or something like that. On the second attempt, it showed the drop-down menu with the options.

It is very good that the state of the drop-down menu of being open or closed is preserved between invocations (i.e., insertions and removals of the devices), thus it removes the need of an extra click on the arrow every time. It still takes extra screen space, but in this case I would call it acceptable.

Section_8 wrote:As another option, you may be able to control what is launched when a device is opened, under System setting->Applications->File associations. I assume the entry for a directory controls this, so if you search for "directory" there, and select that, you should see the list of applications for a directory. You should be able to change the first entry there from Dolphin to something else, such as a terminal, or (maybe) remove everything from that list so that the "open" action does nothing.

That could probably also work, but it's not ideal, because it sounds like an attempt to overcome the intended behavior with something that wasn't designed to do it, and there would still be the "...and Open" words on that button, which is not good cosmetically. I would rather prefer the actual action to be configurable. Maybe some day it will be, because KDE, unlike most DEs these days, does not assume that the user has no brain, so it does not assume that having more settings is a bad thing, and it is being loved for that.

Subsequently I have found that the open/closed state of the drop-down menu that has the "Mount" button is not remembered when the device is unplugged and plugged back in. It means an extra click on the arrow icon is required to open that menu every time a removable storage device is plugged in.