Plugin is broken in Firefox

Since last update. The editor is broken in Mozilla Firefox when there is “Enable full-height editor and distraction-free functionality” active.

Problems:
1) Article area is divided into 2 parts
2) Can’t move images in the gallery
3) Sticky sidebar is glitching

When the function is deactivated, there are also some problems. Can you please take a look at it? Firefox version 80.0b2 (64 bit?)

Thanks.