Does the trainer keep running in the taskbar?
if thats the case, try the following:
you can try to start Task Manager (CTRL + SHIFT + ESC) -> right-click on the trainer process and select 'Expand' -> right-click on the child process and select 'Maximize'
you should run the trainer -> change your display resolution to the lowest value and confirm it -> trainer visible again on Desktop? -> change resolution back to default value and confirm
I'm having the same issue, the trainer is stuck on the intro image. Tried running on administrator, different resolutions and on different Windows compatibility modes.
Possibly the new Windows 10 version update from 2004 to 20H2 to blame?