Since it can be very difficult and impossible to expect providers to follow the rules of the Apple App Store, many have found a job and are developing a promotional service to match Safari, Apple’s browser. This means that iOS device owners can play games on their phones and manufacturers will not have to supply Apple’s requirements.
Sounds like a winner, but unfortunately it looks like Google Stadia, whereas iOS 15 seems to have broken it. According to post on Reddit, Stadia Group Manager shared that iOS 15 could make some changes that make Stadia less playable on iOS devices, as well as how to solve this problem.
Basically, users will need to change some of the Safari by going to Settings> Safari> Advanced> Experiments and disable “WebRTC Platform UDP Sockets”. It is unknown at this time what he will do after leaving the post. Some also say they see color limits playing.
It is not clear what the problem might be and if it is a virus inside Safari or if Stadia needs to be updated to make sure it is compatible with iOS 15, but in the meantime if you experience any problems, then you can fix what to look for so far.