All fixed now after receiving a test version to try. Wonderful speedy service. If only all developers were this helpful.

Thanks for the fast response, and sending me an experimental test version where this issue is now fixed for me.

Tracked as 21279.

Same here on 3064, however for me the window is showing, but is completly empty.
Debug log + printscreen is also uploaded.

Updated my last ticket #7726

Thanks Lowlander. I've sent a support ticket.
This problem gets weirder though. I just updated MM5 to: 2024.0.0.3064. Now, when trying to maximise MM on 2nd monitor, it doesn't flip back to monitor 1, it disappears altogether. I played around a bit and found that it was still running and I could even play whatever was the current track by clicking on the preview on the taskbar. Then I found that I could bring the screen back using the Windows Start key and the cursor keys. Still couldn't maximise it though. It just disappeared if I tried. I wondered where the screen was going when it disappeared and tried plugging in a third screen, which is a drawing tablet. As soon as I plugged it in, MM appeared, maximised on screen 2, where I'd last tried to maximise it. However, moving that window and trying to re-maximise just made it disappear again. Very Strange. If I were to hazard a guess, it seems it is maximising it to a non-existing monitor. I'll have to wait and see what the support ticket brings up. Thanks, as always, for your time and help.
Windows 11 Home
12th Gen Intel Core i5-12400F
GTX 4700 Graphics
32gb Ram

Support ticket: #7765

I'm unable to reproduce with identical dual monitor. MediaMonkey resizes on the monitor it was resized on. Please capture this in a debug log (step 4b) and attach the log to a Support Ticket.

Hi. Just downloaded 2024.0.0.3063 Test build and on my two monitor setup. MM will only maximise to the right hand screen. Restore down sends it to my 2nd screen and maximise from any position on the two screens will only maximise to the right hand screen (main screen). Moving MM to the 2nd screen and dragging to the top of screen to maximise it, just flips it to the other screen.