NAT problem. Unable to create or join party and play games online

Since approximately Yesterday, i'm facing problems with the online services of my PS4. The Internet connection is correct and works perfectly on my different devices at home but on my PS4, it seems that there is a Nat problem that doesn't allow me to create or join a Party and to play online on Rainbow 6. Despite this, I'm still able to play online on NBA2K17, that's why I don't understand.
Obviously, I tried to switch Off&On my Box, my PS4, I tried to change the DNS parameters with 8.8.8.8 and 8.8.4.4 and to open TCP and UDP ports. Nothing works.
Sometimes, the NAT Type switch to TYPE 2 but still not enough.
Could you please help me ?
In advance, Thks a lot !