Steam Big Picture mode may interfere with playing games on GOG via Galaxy. I suggest closing NOT MINIMIZING Steam when playing games on GOG. It seems even if Steam is minimized, when you play a game Steam Big Picture can be activated and interfere with games you play in Galaxy.

I hope this helps some people.

Thanks for the info. I always close it anyway. Even with plenty of RAM I guess for the sake of less clutter I Like to have the minimum amount running.

What do you mean with interfere? What kind of problem have noticed?
I've them opened at the same time and never had a problem.. maybe for the overlay?

I mainly use Windows (10) for games, so I have both set to autoload at startup, can't say I ever noticed any problems.

I"ve never noticed any issues either. Maybe it happens with some specific game?

Also in the "Never had a problem with both" camp, but I don't use big picture mode.
EDIT: Also in the group that says "Tell us what kind of problems because we may not know what we're experiencing, or we may be able to help you solve your issue"

how about just close Steam big picture mode when you're done with it. Duuuuh!