Possibly some old configuration on your backend from the letsencrypt beforehand?
Are you referring to the original HTTPS configuration for Let’s Encrypt for domain.com? I haven’t disabled that yet. Should I entirely disable HTTPS for the Nextcloud server?
Have a look at your next cloud backend http logs to see what requests are arriving there and what HOST( http header ) it’s trying to connect to on that IP.
I’m not entriely sure where to find what you are referring to. I checked the Apache logs for Nextcloud, and I didn’t find anything.