422 Error "registry status prevents transfer" when trying to transfer site to cloudflare registrar

I filled out the form to transfer my domain to cloudflare registrar (as I have done for one domain previously), and when submitting the form, I get this error screen:

Looking in the console, the server is giving a 422 (“Unprocessable Entity”) response code, with this payload as the response body:
{"result":{"message":"mainsqueeze.dog registry status prevents transfer"},"success":true,"errors":[],"messages":[]}
Any ideas for where to look next? Thanks!

I waited 10 hours and made the transfer without any problem. I had changed my domain servers very shortly before this, so maybe it was something to do with that.