Hikvision replaced the camera, but I recently had another Hikvision mini-dome camera get a stuck IR cut filter (half way open). The seller wouldn't replace it because I had painted the case. I tried cycling between day and night but it didn't work. The filter didn't budge and the normally clicking sound of filter was now silent.
It turns out it was a simple fix. The lens assembly came apart easily. There were 7 little screws holding it together. I didn't have to disconnect any of the little wiring harnesses. Once apart I could see the filter was stuck half way out. I used a phone cleaning brush to rotate the filter on and off a couple of times. The brush is a small green plastic rod with a tiny amount of felt on the end. I left the filter in the off position and reassembled the camera. Upon power up I could hear the clicking of the IR mechanism. The IR cut filter is now functioning normally.
I think the problem occurs if these cameras are positioned where they gets too much direct sunlight. Both cameras that failed got a lot of morning sun. I have several other mini domes in shady areas and they have not encountered any problems.