Lock on Thule tow bar rack stuck!

I don’t usually bother locking my Thule rack on to the tow bar but today I did and now it won’t unlock. I have tried much key waggling and GT85 but the key still won’t turn.
Any ideas on how to get the rack off?
If all else fails what’s the best way of breaking lock without damaging the attachment mechanism?

It may be necessary to get the weight of the rack off the locking mechanism before the key will turn. Can you unbolt the tow hitch from the vehicle?

Try lifting the tail end of the rack to take some of the pressure off the lock mechanism as you turn the key.

I’ve had this when the lock had rotated in the plastic…

As above lift rear and try to raise handle.Less intuitively try flooding lock with light oil,working theory being that one of the tumblers in the lock is stuck.

Thanks guys, tried all of these and it finally turned. Must remember not to lock it!

Ha. Mine is such a bugger to get off I never bother locking it anymore.