This doesn't happen for my first screen. I've also tried with other devices having the same problem which it keep hiding itself when my mouse is still hovering over it. Setting the second display as main display seem to fix it, but first display will have the same problem. So it is happening for display that is not main display i think.
Video on first devices: https://youtu.be/pcqSXoF6usM
Video on second devices: https://youtu.be/i0XI2zqENhM
Another thing is, if I managed to click on the tab when it is hiding itself, this happen switching tab will fix it.
Another problem is when you pull a tab from another display into the fullscreen edge, this will happen sometimes it might even freeze the windows for a few second.
Video: https://youtu.be/js-OqzQeZKo
After watching the video you might also see every new tabs that i opened is all white only even if I open a website, i am not sure what caused this. It happened to me only once before. Might also because of the glitchy fullscreen. Restarting the browser seem to fix the white screen bug or you pull the tab that is not effected after opening a white tab.
Video of fixing it: https://youtu.be/h0ZbduA7LbA