A VHS tape that stops half way through

I've got a pile of VHS tapes I've been going through to find anything worth keeping, but there's one tape that's displaying some odd behaviour. The reels imply there's half a tapes-worth left to play in the cassette but my VCR will stop playing it and automatically rewind as if it's hit the end. I manually pushed the reel on a bit before trying again and the same thing happened after ten seconds. Only when I did it again did it seem to play normally. There doesn't seem to be anything remarkably different about the cassette and the player is a ten year old Panasonic combi that seems to play everything else without fault.

Has anybody ever heard of this sort of thing, and any idea what might be causing it?

Sounds like something on the tape itself is snarling the heads and causing it to rewind.

This? https://en.wikipedia.org/wiki/Sticky-shed_syndrome

That could be it, and that's also explained a lot of the noise I've been hearing when I've gone through other tapes.

Sometimes you may need to fast-forward to the end and rewind back (from stop, not through playback) and it can help with issues like these on tapes that haven't been played for a while.