I’m experiencing this bug also and, recently, it’s worse than before.
To workaround, I sometimes have to adjust the window size AND refresh. This certainly started with the update about four months ago. But was there a recent update?
This is board size thing with seems to effect smaller board sizes more, or maybe it’s just because smaller board sizes don’t necessarily take up the entire screen. There is a similar bug that happens every single time when reviewing smaller board sizes.
I use a Chromium-based browser. I’ve also heard this can happen on Firefox and Chrome.