I checked your debug logs and didn't see any obvious errors or issues, so it is currently impossible to tell if the issue is caused by rclone, wps, your local disk, the webdav server, something else - or a specific combination. I therefore suggest you try to eliminate as many possibilities as possible by further simplifying your reproduction.
You could try eliminating wps by reproducing with another editor, e.g. Word, LibreOffice or WordPad.
You could try eliminating you local disk by checking what happens if you do the same sequence in a testfolder on the disk holding the rclone cache, probably C:
You could try eliminating your webdav server by testing on a mount of a local folder, something like this:
rclone mount ./testfolder T: --file-perms=0777 --dir-perms=0777 --vfs-cache-mode=full --volname="test" --human-readable --cache-dir=cache
You could try eliminating rclone by mounting the webdav server directly in Windows by opening Explorer, right clicking on "This PC" and then selecting "Map network drive".