I would 99% guess that the name resolution fails. Did you update the hosts file? Can you verify in a Windows terminal using e.g. ping nextcloud.local that it is redirected to 127.0.0.1?
The access via browser to the IP is not possible. There is an nginx reverse proxy in place so that all possible NC servers (stableXX as well as nextcloud, nextcloudX) and all other HTTP servers can be accessed using a single port (80 or 80+443 with HTTPS). To do this, the browser must claim âI want to talk to nextcloud.localâ, which the browser is not doing when using the IP address. (This is done via the Host header in the request, just FYI).