Exception HMAC does not match

Hi all

I changed my NextCloud host address from xxduckdns.org to xxyy.duckdns.org because overnight the https://xxduckdns.org wouldn’t connect in https.
Why ? no idea and couldn’t get it to work/connect again so I changed it to https://xxyy.duckdns.org which is working fine

I’m now seeing in my logs :
Exception
HMAC does not match.
Could not decrypt or decode encrypted session data

This error is only a couple of days old , so it seem tied into me changing the duckdns address

Have seen nothing about this via Google that seems to be linked to my problem so any help clearing it up would be nice

Thanks

running Nextcloud Hub 7 (28.0.1) Debian

https://help.nextcloud.com/search?q=%22HMAC+does+not+match%22