So it’s a focus rectangle. I don’t know what I can do about it, but I’ll look into it.
The game will continue to be developed as usual.
I think this is caused by a wrong initialization bug, which has already been fixed for v.125. Please test it again and let me know.
Changed in v.125 
Idea
Fixed in v.125 Bug
Are you using actual fullscreen mode? Windowed and borderless are forced to use V-Sync by the window manager (even though the game might be internally rendering faster)
The game’s frame counter is updated 8 times per second, but it only shows the last frame’s duration (well, inverse duration). It’s not an average. It measures the time taken between two successive frame buffer flips – as measured by when the draw call returns, not when the GPU actually gets around to flipping the buffers (due to internal buffering or frame “pre-rendering” this might not happen immediately). Also, timeSetEvent (failing that, just plain Sleep) is used to wait until a specific instant, which has both accuracy and scheduling issues (even more so if you’re running it under Proton), so it’s possible it waits for too long (or too little?)
This looks like a GPU driver bug. I can’t do anything about it.
On the list.
Auto-updaters are convenient, but internally they are quite complicated and not something I have time to do (or even want to do).
That’s going to draw way more players, which is not desired. There will be FPS issues for the players, and balancing issues for the server.
Christmas Edition will be added on the 15th.