You're hunch seems to be dead on. It seems to happen mostly when it's going up. It happens starting from all floors I think. And, it occurs every single time.

What happens exactly is someone presses a button. The car jerks a little and then moves to the desired floor. Then, there is a wait for a few minutes. And, then the door opens.

Today, the car's safety got triggered and they were working on it all day to get it off. This is an office building so it's been a nightmare with the tenants screaming bloody murder.

Trust me. We don't cut any corners and make sure that the elevator professional does all the work. We sign off on all work that they suggest. We definitely want this to be done the right way.

And, thanks so much for everyone's help. Hugely appreciated.