Video Assist 7" 12G HDR won't start on batteries

It's a brand new unit. Won't start on batteries. After connecting the power adapter, running and shutting down, I can disconnect the power adapter, and then the unit will start on the batteries.

After a few hours, the situation is the same: No battery start -> power adapter for a moment -> shut down -> start on batteries.

What is the reason? Is there any solution for this issue?

The newest firmware didn't change anything.

I have the same problem. Worked great on my bench. First I plugged in AC power, added the batteries, took off AC power, turned the unit off. Then turned it on with batteries only and it worked. Today on set nothing! Batteries are new! They worked 12 hours ago but the unit would not turn on. What's the fix?

Today my 5" Video assist would not start on batteries again even after 12 hours previously of starting on batteries. So I plugged in the AC power to the monitor to start it up. But this time I DID NOT plug in the other end into the AC outlet. And it started with one battery attached!
Waiting for a BM answer.
Bob

Today my 5" Video assist would not start on batteries again even after 12 hours previously of starting on batteries. So I plugged in the AC power to the monitor to start it up. But this time I DID NOT plug in the other end into the AC outlet. And it started with one battery attached!
Waiting for a BM answer.
Bob

I signed up to say I has this exact problem, and your post led to a solution for me. What an absolutely baffling bug. Did you ever receive a response from Support?