Indesign always forgets app size and position in latest 2020, V15.0, Windows.
I thought that this issue was well and truly over after update patch with previous versions but here we are again, 2020 version 15.0 and still happening.
Please fix as very annoying, also, this may be related but indesign main frame (top tool bars) completely disappear when first minimising the application, leaving the vertical tool bars behind, the only way to retrieve the main top toolbar is to re-start the application. Amateurish!