Plesk Lets Encrypt Certificate Auto Renewal

Hi,
I am just getting started with Plesk on Lightsail. I have successfully issued an SSL to my domains. However, I keep getting errors when the system tries to auto renew the certificate. I cannot seem to find an answer. Can anyone one help or point me to some documentation?

Here is the email I keep getting...
Could not secure domains of admin (login admin) with Let`s Encrypt certificates. Please log in to Plesk and secure the domains listed below manually.
Securing of the following domains has failed:

• 'example.ca'
  Missed domain names failed to pass validation: webmail.example.ca

The following domains have been secured without some of their Subject Alternative Names:

Could not renew Lets Encrypt certificates for admin (login admin). Please log in to Plesk and renew the certificates listed below manually. Renewal of the following Lets Encrypt certificates has failed: