I have already deleted and recreated the _acme-challenge record 2 times, no success.
I waited 1 day.
I checked the DNS servers for my domain xplorr . eu . org:
ns1 . epizy . com
ns2 . epizy . com
ps. I had ssl keys before, without a problem, with an old _acme-challenge CNAME record
Due to the outage from yesterday, some domain and DNS related data may still be outdated. iFastNet is working to correct all of this. Please have patience until this is fixed.