I have samsung galaxy A51 and the chat features work for some conversations but not for others in the stock massaging app! I have tried everything from clearing the cache to clearing data, is there anyway to disable or uninstall the app?
If it doesn't work for some conversations, does the other person have RCS messaging? You can just turn off messaging in advanced settings and revert to SMS.
I have the s21+ and I think the chat features only work fully from Samsung phone to Samsung phone if you message a non Samsung user then you will only get weather they have seen it or not