Basically the title. When using WebDAV to sync files, there is a maximum file size, defined by NGINX option client_max_body_size. Increasing it can be done by inserting the following example in "Extra options":
This should be a GUI option, since it is essential for a protocol meant for data transfer. If it was a GUI option, it would make it a lot easier for users to identify this being the cause of a problem when trying to upload data via WebDAV.