Mail server sends SSL which is self-signed and is expired

Hi, I was using CyberPanel to host a WordPress website and a mail server for three months without a problem. I used the built-in SSL tool of CyberPanel, and after three months, the certificates expired. I’m trying to renew them, which worked with my website without a problem. But when I try to login any of my mail accounts, I get an error saying my SSL is expired. I checked both and from my browser and they both state that they have 3 more months to go as I just renewed them, and are issued by Let’sEncrypt. But connecting to my accounts from, for example, Apple mail or Outlook for Windows, I get an error and when I inspect the certificate, the issuer is my own domain, and the expiration date is due.

What might be causing to distribute two different SSL’s? Or am I missing something… Thanks!

By the way, my website I’m talking about is