Without updating to a newer version, you can set buf_size to 64 in /etc/davfs2/davfs2.conf to get stuff working again.
OpenPGP_0xAF605C87F9E5AE94.asc
Description: OpenPGP public key
Description: OpenPGP digital signature
As mentioned before, this issue appears to be fixed upstream:
https://github.com/alisarctl/davfs2/commit/4c6a10d7854a34ecf0cda5ee750441602a2da945
