Increased ping in 2 games

I had Att Fiber since 2021 and I used to get 29 ms in Genshin and 39 in star rail. Since last month, my ping has increased to 40 ms and 50 ms. I used a free vpn called windscribe and got the ping lowered to 35 ms in genshin. The ping increase is not that much but I was wondering how to get att to lower the ping since it's the only games that had it's ping increased. These games are both owned by hoyoverse btw.