Not really.
Current state is, that I moved my Server to entirely new hardware a while ago. It was all fine for some time but still randomly happens. Sometimes all is fine for 1-2 weeks and then suddenly, no external connection possible. But as a workaround now I can just switch between manual port or automatic port in the “Remote Access” Settings. If the port changes, it will work again for quite some time.
So I basically switch between the default 32400 port and the automatically generated port forth and back. Port forwarding makes no difference.
