Hi - for some reason, Cloudflare failed to pull in the existing records so I’m setting them up from scratch. When I try to add the first record, a blank A record, I get the 81057 error.
How long ago have you added the domain? There is a known issue with the import seemingly failing but eventually succeeding. It might be that the records already exist but are not shown. Just wait a bit and check whether the records show up later.