I've had this happen a few times to me now and it's starting to get annoying. I ask a follower to join me and for a while everything works fine and they move around / kill things as normal. Then for some reason they start blocking and don't stop. Every time I unsheath my equipped weapon they do as well but automatically start blocking until I sheath again. I've tried saving and loading again, console commands such as resetai, kill / resurrect, disable / enable and simply dismissing and rerecruiting the follower but none of these fix it
It's pretty bad as not only does this mean that the follower rarely attacks (occasionally they'll hit enemies before reverting to blocking) but it also means that they move at a snails pace across dungeons and the wilderness which often results in them being slaughtered when a dragon attacks
Has anyone else come across this bug and maybe found a fix? I've checked google but only found one relevant topic and it didn't have a reply

Ah, fixed it. For anyone with the same problem; bring up the console, click the broken follower and type 'tc' w/o the quotation marks. This transfers control of the character to you, press block and then release and type tc into the console again and they should be fixed