Hi there,
I have an unusual bug. My setup is a new 16" MBP M1, and I'm using an LG 5K monitor for my secondary screen. When I launch indesign, it will open up with a giant looking UI. Everything is massively scaled up. However, if i unplug my screen, quit indesign, then relaunch it just on the laptop screen, then reconnect the monitor, it will now look the correct size. This problem is independent of the new UI scaling tool, i've tried that. Besides, it's like comically big.
TL:DR I think when indesign is launching, its reading the dimensions of my laptop screen, then scaling it up to my larger secondary monitor.