What does renewal validate?
ACME must confirm control over the domain. If the domain points elsewhere or DNS records are inconsistent, renewal may fail.
After migration, both the website and validation-related records should be checked.
ZeroSSL/Sectigo and Let's Encrypt
On Hostilla.pl, free SSL can be provided through automation available in the hosting environment.
Projects requiring organization or brand validation may consider OV, EV, VMC or CMC certificates.