Rainbow Six Siege ping becames to high when I enter multiplayer (PC)

Ok, I'll try to be very descriptive and, also, short. My ISP uses CGNAT. If a launch a default R6 game, it put me in South Asia servers (ping 20ms), but I live in South America. If I enter a multiplayer game, to ping goes up to 130ms. If I force a brazilsouth server (Game.ini config file), the ping goes to 130ms. Ubisoft says it must be that my TCP/UDP ports are closed. I have already open ports in my router and, also, try to do the same on windows (netsh or something). If I use a VPN, the ping goes back to normal (20ms). After all this, my question is: is there a way to configure something on my side to solve this?

Thanks.

Seems there might be something with your ISP.

Try to contact them and figure out if gaming traffic is put as 'non priority' or something like it. Would explain why you get a high ping even if you force the server, but passing via VPN you suddenly got an ok ping. (With a VPN your ISP has no clue to what you are connecting)

Might also explain why you automatically connect to asia. The ISP might have configured to give you the crap connexion if you connect to most of ubisoft servers, but the asia one has been forgotten and it suddenly has the best ping of the list.

To wrap things up: Call your internet service provider and poke around to see if traffic related to gaming is not treated the same as normal Facebook or Youtube traffic.