Ich habe
#Webfinger Support
Redirect 301 /.well-known/webfinger /index.php/.well-known/webfinger
ergänzt.
In der .htaccess stand weiter oben
RewriteCond %{HTTP_USER_AGENT} DavClnt
RewriteRule ^$ /remote.php/webdav/ [L,R=302]
RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteRule ^\.well-known/carddav /remote.php/dav/ [R=301,L]
RewriteRule ^\.well-known/caldav /remote.php/dav/ [R=301,L]
RewriteRule ^remote/(.*) remote.php [QSA,L]
RewriteRule ^(?:build|tests|config|lib|3rdparty|templates)/.* - [R=404,L]
RewriteRule ^\.well-known/(?!acme-challenge|pki-validation) /index.php [QSA,L]
RewriteRule ^ocm-provider/?$ index.php [QSA,L]
RewriteRule ^(?:\.(?!well-known)|autotest|occ|issue|indie|db_|console).* - [R=404,L]