Since iOS 18, I also have the problem that while playing PUBG Mobile, a kind of scratching and desynchronised noise appears sporadically over time. This is an extreme hindrance to playing. The only workaround is to switch Bluetooth on and off while playing so that the Airpods reconnect. This is very unfavourable. I have tried everything, changed various settings, tried or avoided different modes, NOTHING helps. So it seems to be a serious bug!
I use an iPhone 15 Pro Max and Airpods Pro 2 with latest versions.