I had only 1 free Theme installed while exploring my-this- new phone, but can't get rid of it and is appears as some background as well. Went in My Stuff..but can't delete it.
Try wiping the cache partition on the phone and that should resolve the issue. To do this, just search 'how to wipe cache partition Samsung A22 5G' and you should find what you are looking for 🙂. Hope this helps! 😎