Saving a contact glitches and the contact doesnt stick

I’ve had this issue a couple times where when I save a contact it kinda glitches? It doesn’t happen for every new contact I save, just happens randomly. Basically I’ll go to save a contact, I add the name and all that and then it shows up normally with their name. When I refresh the messages app it then only shows their phone number as if I didn’t save the contact info at all. After trying to save as a new contact a few times and it not working, I tried adding to an existing contact and saw that there were multiple copies of the same contact info. When I added the number to the existing contact info it stuck for a day and then reverted again a few moments ago. I don’t understand what’s causing this and why the contact info isn’t sticking.