Flappie, excellent data, thanks!
I've tried some more and here is what I've found:
1) Ports are not so random, 49720 appeared again
2) So far, other ports are working, but 49720 is not
3) i don't have any ports forwarded except 10308 and 5002 for DCS/SRS
4) I could try to forward 49270 and check stability
5) If that's the case, do you have a list of ports so I can forward them all or something like that?
thanks!