When opening the "Edit in Textmode" / "Im Textmodus bearbeiten" (cmd + Y) the window will not show up.

I have tested this on several macs in our company with different kind of additional monitor setups or no extra monitor attached.

InDesign Version 15.1.1

Steps to Reproduce:
1. Take what ever textframe you want => Cmd + Y or rightclick "Im Textmodus bearbeiten" / "Edit in Textmode"
2. The Window will not show up and you might think it is broken...
3. It shows up when you go to New => Page for example (Or probably update the UI in any way? not sure - did not test much further but this works)

Screenrecording attached