Hi,
I use kdenlive on laptop and I use laptop display to make changes and second display (LCD monitor) to display project monitor in fullscreen mode. Now (in new kdenlive version) project monitor in fullscreen mode is always on first display, never on second.

how to fix it?

i have just 2 monitors and when i want to take a look to a full-screen project monitor i just double click on the image displayed on projectmonitor (docked in kdenlive) , and the full screen project monitor opens on the "opposite" screen on full screen. (working on monitor 1 and 2)

I'm using Windows and latest nighly build of kdenlive.

This way worked on old kdevlive. But after redesigning, it's still on 1 display, never on 2
I use Kubuntu (the newest). I prefer Windows, but kdenlive under Windows is terrible slow, so I have to use it under Linux.

well.. time to me to add a PC with an updated Linux distribution to do some tests

I am also facing the same issue. With previous versions, I was able to simply drag the preview monitor into my 2nd display and double click to go into full screen. I could then just leave it there and use my first screen to splice my video together and do color corrections and effects. Now It always wants to stay on screen one. I drag it into screen 2 and double click and it goes full screen but on monitor 1

just tested on fedora 31... moving the preview window on second display...and i can't enlarge to full screen at all.. double clicking is doing nothing.

I don't see how to move the monitor panel to another monitor. There is no "docking title bar" to grab. I've checked the View -> Show Title Bars. Has this feature been removed from the monitor panel?

I'm using kdenlive-19.08.3-x86_64.appimage on Ubuntu 18.04.3 LTS