@Vaghrad I shall bless you with more knowledge.

The most correct thing to say would be; "Whoops, I forgot to renew my X.509 certificate signature".

There are differences between the X.509 versions used for SSL and TLS, although generally v1.2 and v1.3 use the same certificate format (although I guess TLSv1.3 may support different fields, or forbid fields that were accepted by v1.2).