Practice Lockboxes broken

[Maeven]

In Alther's Mill, just outside Redridge, there are about six lockboxes which are usually used to train up the pick lock skill for rogues. However, I went out to try my hand at it and the skill didn't raise up, though I was only at level 10. I gave it several goes on each box, but no joy. In fact, all the boxes were opened and didn't close for a retry as they should, and resultant clicking on the opened boxes to attempt to reclose them gave the text "Item is locked".

Cheers