GUI Window resizing on Linux seems to be broken for some setups

[kodeah]

Bug Description:

Resizing the window with the mouse is broken in my setup: Releasing the mouse button does not stop resizing, instead a click into the GUI window is required to do so.

Surge XT Version

• Version: Surge XT 1.3.4.f7b97c6
• Plugin Type: Don't know, I use the GUI app from the deb package.
• Bitness: 64-bit

Reproduction Steps:

Steps to reproduce the behavior:

1. Open the GUI app.
2. Press the left mouse button down on the window border to start resizing.
3. Drag the border to change the window size.
4. Release the mouse button: The resizing does not stop, the mouse-up is practically ignored and only another click into the window stops the resizing. (Note that this click is more or less difficult to achieve, because when I move the mouse into the window, the window gets smaller, since it is still resizing.)

Expected Behavior:

I expect the resizing to stop on mouse-up, and the window to keep the size it has at that moment.

Computer Information:

• First OS: Linux Mint 22 with latest updates
• Second OS: Linux Debian Testing with latest updates.
• Graphics Card: NVIDIA Corporation GK107GLM (Quadro K1100M); its ooold ;)
• Graphics Driver (Debian): Nouveau
• Graphics Driver (Mint): Whatever the live version brings for a driver by default.

Additional Information:

I guess it is related to #7409, since when using i3wm, I get further glitches in addition to the described one, for example sometimes the window goes black, but I didn't analyse the behaviour in detail yet.

Also, thanks so much for the tool, it is great!