NC does not sync .mdb and .bak files

Hi all,
after setting up a local folder to sync to NC i find the Windows desktop cllient does not sync all files, e.g. .mdb, .bak, .swl. files. How can i achieve this? I am receiving errors of the sort
“No E-Tag received from Server…” and
“405 method not allowed” on "PUT…

Any help appreciated!

Hi again,
found the solution: it’s a hosted Nextcloud, and the Web Application Firewall did not permit certain file types. I was able to access the firewall rules through the providers web config panel and put in some exceptions to allow for the corresponding file types. I had found the “firewall hint” previously on this forum, not understanding, that it was not the Windows firewall, but the one on the web hosting provider’s end.
Solved!