No itz wasn't always Azure, actually it never was, just for the mailserver / nameserver since April 2019.
By coincidence today my new Provider (Aruba) solved the issue by removing DNSSEC...
thank you anyways for your help!
On Friday, July 5, 2019 at 3:38:52 PM UTC+2, Alex Dupuy wrote:
It appears that you have resolved the DNSSEC problem with your DNS provider (was it always Azure?) by removing the DS record for your domain.