It could be because Facebook doesn't think you are who you claim you are. Normally if you put a name that isn't your true first or last name they'll do that. There's also glitches where they will think that you're going under a false alias and they'll ask you to change it if they find its a bug.
Facebook asks for too much info. It's why I don't share or even use mine like that anymore
However long ago I had a fake girl account that had a lot of friends and I had no issue nor a request to change the name while this issue was happening to everyone else. (Never got why all the info was made up LOL)
After a month think I deleted it since I only made the account to test something. (I didn't even use real photos either the account just had a picture of a wolf just cause I liked the photo)
But this was in like 2013 or 2014 or whenever Facebook started suspending people with fake info. (The account was harmless BTW LOL it was funny though how people would try to hit on someone with no photo or any kind of way to see if I was who I claimed I was.)
Then again I'd tell everyone single not looking so they'd stop with that.
The test was to see if females get more friend requests than males and to see if Facebook would ever catch on to the account not being real.