Greetings from Moscow, guys!
When I connect the second display to my Macbook Pro 15 (2018) through HDMI or Thunderbolt, cursor on pastboard and pages fields behave drunk. This problem found on plugged display and build-in display too. Only on Big Sur from developer betas in 2020 to 11.3.1 now. When I disconnect second display — everything works fine.
Updates, reinstalls, setting changes did not help me 😞
Something to report in UserVoice
UPD: One more thing. When InDesign window inactive — cursor inside pastboard moves fine. When I just click to InD window and make it active — cursor moves incorrect.
UPD 2: When I turn off the rulers — 'drunk' problem is solved.
Please check, why rulers affect the work of the cursor.