Could you do the test with another emulator and tell me if the same thing happens??

Also when the mGalaxy-Window is minimized during change the games, Mame disappears.
I don't understand your sentence very well, could you clarify this ?


When I quit a game in MAME and get back to mGalaxy ...

Can you check if, once quit, MAME does not appear anymore in the task manager?
You can get access to the Task Manager by pressing CTRL + SHIFT + ESC at the same time


When i quit MAME, it no longer appears in the task manager. Also when the mGalaxy-Window is minimized during change the games ...

There are more posts describing the same problem. Also my MGalaxy window somtimes getting minimized (happen for all MAME-Games) and has to be resized with the mouse. This problem does not occur with an older version (6.0). Till now I haven't found a solution for this annoying problem.
WIN10 ...