It looks like the issue is with some edge case handling for detecting whether a share path is locked. We were handling EZFS_NOENT but not EZFS_INVALIDNAME. In 25.10 we’re transitioning from our old pylibzfs library (not thread safe) to a new libzfs python library that is thread-safe (allowing us to gradually eliminate using a process pool). The result is that the backend is much faster / reliable, but we will have a few wrinkles to iron out here and there.
Being backported for 25.10.0