Nextcloud Backup strange error

[hansdampf]

I am having a really strange error whit my nextcloud-backup:

Code Select Expand

2024-07-09T08:44:40 Error config {"url":"https:\/\/nas.xxx.xyz:8443\/nextcloud\/remote.php\/dav\/files\/opnsense\/OPNsense-Backup","content_type":null,"http_code":0,"header_size":0,"request_size":0,"filetime":-1,"ssl_verify_result":0,"redirect_count":0,"total_time":60.034358,"namelookup_time":0.001119,"connect_time":0,"pretransfer_time":0,"size_upload":0,"size_download":0,"speed_download":0,"speed_upload":0,"download_content_length":-1,"upload_content_length":-1,"starttransfer_time":0,"redirect_time":0,"redirect_url":"","primary_ip":"","certinfo":[],"primary_port":0,"local_ip":"","local_port":0,"http_version":0,"protocol":0,"ssl_verifyresult":0,"scheme":"","appconnect_time_us":0,"connect_time_us":0,"namelookup_time_us":1119,"pretransfer_time_us":0,"redirect_time_us":0,"starttransfer_time_us":0,"total_time_us":60034358,"effective_method":"MKCOL"}
2024-07-09T08:44:40 Error config cannot execute MKCOL

My nextcloud is sitting on a xigmanas, certs are generated from opnsense, the nas shows cert is ok, valid and trusted (self signed) -> "http_code":0 and "ssl_verifyresult":0.
But what i dont understand is the MKCOL-error. Searching the net doesnt show up relevant infos...
My opnsense is the latest (OPNsense 24.1.9_4-amd64). Same with my xigmanas, nextcloud is 29.0.3.
There are no errors in my nextcloud installation, i generated the App-password for use with the opnsense-backup.

Any help would be great!