The docs only seem to document entries for caldav/carddav. Besides using index.php rather than public.php, the format of the rewrite is also different. I have the following entries which got rid of the warnings:
RewriteRule ^.well-known/carddav /nextcloud/remote.php/dav/ [R=301,L]
RewriteRule ^.well-known/caldav /nextcloud/remote.php/dav/ [R=301,L]
RewriteRule ^.well-known/webfinger /nextcloud/index.php/.well-known/webfinger [R=301,L]
RewriteRule ^.well-known/nodeinfo /nextcloud/index.php/.well-known/nodeinfo [R=301,L]
Don’t forget to also restart httpd.
Can you post the entries you have?