Minimizing maximized window with Custom Window Frame -- closes the app

[WallK]

On Windows 11 (24H2), Lagrange 1.18.5

When trying to minimize maximized window (with custom window frame option enabled) -- app closes instead of minimizing
Non-maximized windows behaves as expected and minimizes fine

STR:

1. Enable Custom Window Frame option in preferences (and restart the app)
2. Maximize window
3. Try to minimize window

ER: Window minimizes

AR: Window closes