One VIM 3 has weaker USB output than another VIM 3?

I ordered 3 VIM 3 units last year around this time. One I gave away, one Is the problem device, and another is the control device.

The problem VIM 3 causes my 4.3" touchscreen to dim and flicker noticeably while playing Youtube videos. I exhaustively changed all the accessories over to the control VIM 3 and it has no such problems.

Both the problem VIM 3 and the control VIM 3 have the exact same software configuration. Both the problem VIM 3 and control VIM 3 were attached to the same 4.3" touchscreen, 4G cellular device, and USB hub in the same plug configuration.

I plan on ordering a replacement for the problem VIM 3. Is there anything I can check for?