I'm unfortunately using InDesign 2026.0.2. One of my coworkers had the brilliant idea to update on day 1 ...
I'm on Apple Silicon M1, with 2 monitors. Now, when I open up any document (I don't use application frame) it opens normal, as in any version before, size of 1 monitor, between upper task bar and macOS (26.1) dock. But as soon as you do anything, including opening a second file, the canvas expands way beyond the lower end and the right side of the monitor, making it impossible to work on the lower part of the last page of a document. The only way to avoid it, is to resize the canvas window as the first step after opening. Still opening a second file ruins that work around.
It's annoying, as InDesign was actually for me the only Adobe program that was made with usability in mind. Using and loving it (mostly ;)) since version 1.5. And now I'm spending more time closing and opening files than actually working on them.
Thanks for helping me with the problem.