Have you changed the nameservers since you last posted?
I think this is a domain issue, not a hosting issue
Do you get the same error with Cloudflare?
On second thought, maybe removing and re-creating the account would do something (Take a backup first) as maybe the control panel integration messed something up…
the first is to delete the domain from their system and then add it again
after that config. custom NS and then wait at least 30min-24h
the other is to go into Freenom settings
and return to their default NS and wait 24h
then put the custom NS back and wait at least 30min-24h
P.S. You don’t have to wait 24 hours
it is important to make some drastic change so that the Freenom system is forced to update DB and everything else in their system.