Oooh Jimmy Carr has something to say about maths 
Back on topic I’ve seen this happen now and then to un-aggro’d wildstocks around my bevelled stuff but not consistently enough to make me think bug…
So you mainly see this occur around bevelled blocks?
I’ve personally only seen this happen at lattice + bevel blocks.
Thanks for the replies. I’ve added the video links and the comments posted here to the bug database.