Can't remote connect to nextcloud

I tried setting up the remote connection to nextcloud by following this guide. After adding the service, it doesnt ask for a login. When I do ‘edit service’, I see that my host is ‘https’. After re-entering my host, it just adds this line to the root path on saving.

My settings->
Host: https://nextcloud.host.com/
Port: 443
Root: /remote.php/webdav/

After saving->
Host: https
Port: 80
Root: //nextcloud.host.com:443/remote.php/webdav/

Does anyone have an idea on how to fix this?
Thanks

My Nextcloud files app in the webUI lists the WebDAV url as:

https://subdomain.domain.ext/remote.php/webdav/

This is noted from the bottom left corner cog icon in the webUI.

In LibreOffice, change the host to:

subdomain.domain.ext

select if you have https enabled or not

Change the root to:

/nextcloud/remote.php/dav/files/USERNAME/

Change the URL/host and username accordingly (not caps just changed for emphasis)