Port forwarding not working.

I've been trying to play Red Dead Online and I am experincing constant disconnects. After several hours of speaking with customer service from the developer we figured out it was connected to certain ports not being opened. I tried to forward certain ports myself in the router settings but when I tested these ports with this site thttps://www.yougetsignal.com/tools/open-ports/ with the game open they were still being reported as closed. The only solution I've found that works is setting the router to "Default DMZ Server" but this apparently opens me up to huge security risks. I wanted to come here and see if anyone had a solution or at the very least inform Netgear this is an issue. I don't have much experince messing with this kinda stuff so it's possible I've missed something.