I experimented with the issue on my system. The window minimized to the lower left corner and the top was visible and the expand buttons were visible to restore the window with each attempt.

I assigned different vst's for the different instruments as well as applying some of the PGMusic DxI's and that had no effect on the window and restoration of the window for each track worked.

It's working as it should on my system.

Have you tried to open the Plugins window from another track when you've minimized a window. In other words, if you accidentally minimized the bass track, attempt to open the plugins window from the piano track and you should have the option to select the bass track from that window and close it properly.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.