Collections work great except for ...

Thoroughly enjoying the new 5.1 release with the introduction on movie collections.
The new release scanned my movie collection and placed all the relevant movies into their respective collection except for two movies:

Fantastic Four & Fantastic 4:Rise of the Silver Surfer.

I have checked and reloaded fresh metadata for both these movies. They are grouped as a collection on

Any reason why just these two movies wouldn’t be grouped into a collection?

OK, moved up to Infuse 5.2, deleted the old SMB (CIFS) library shares, deleted the DLNA share, and created the Library from NFS shares.

Everything works perfectly well now (no stuttering/pausing problems with high bit rate 1080p movies off an SMB share, no watched indicators changing on me).

All metadata rescanned and working perfectly well. All movie collections established properly … Except for Fantastic Four and sequel. Arrrgh. Frustrating!