I have been flogging mine in the snow for the past couple weeks. Have you called ARB customer service? They should be pacific time zone and they are always pretty helpful.
Are you absolutely sure your rear end is still locked up? Are you getting solenoid to "psst" after disengagement?
These ARB's can be amazing, and one big headache in the same trip. You can jack up your rear end and see if your axles are locked with the system off.
