@Eooooq I just got word that the error code 9836 in your setup translates to A bad protocol version was encountered, so this sounds like an issue with the TLS ciphers and/or version. Can you make sure that the server is also supporting recent cipher suites and TLS versions and not just outdated ones?
@daniel_rie Alright, thanks for verifying. Can you check your logs (click on your profile picture → settings → report a problem) and send them to your mail and upload them here then (at least the relevant parts)?