Chat settings is greyed out and occasionally pops up where you enter your number for chat settings but when I enter my number nothing happens and chat settings is still greyed out
Try wiping the cache partition on the phone and that should resolve the issue. To do this, just search 'how to wipe cache partition S10+' and you should find what you are looking for.
Another solution could be, try entering a different phone number, then change it to your own phone number. Hope this helps! 😊