ugh same!! why does my facebook keep saying session expired?? it’s been happening to me too and it’s so frustrating. i found that turning off my vpn fixed it for me. maybe try that if you’re using one? idk why fb hates vpns so much but it worked for me.
also, check if your app is updated. sometimes the older versions just don’t work right.
also, check if your app is updated. sometimes the older versions just don’t work right.