Social media isn’t working with cellular data

My cellular data hasn’t been working for several months. I think it started when iOS 15 came out and it hasn’t work since then. it doesn’t work for apps like YouTube, tiktok, Snapchat, Instagram, etc. i had the XR And ungraded phones to the 13, switch sims card, restarted all my settings, I went to my carriers and they said to contact apple. I tired about almost everything. I still can call and message people. just apps don’t work. I deleted them and reinstalled them to.