I’m having the same as you, changed the shell and show the same signs as you. [br]
swapped the batteries and still the same problem, no power. No rail lights and only works handheld (works 50/50 had to remove and put em back sometimes for it to register) battery indicator on switch also displays it’s low (red) even though I know it’s fully charged.
Gonna try purchasing a rail replacement and see if it works. If anyone has an answer to this, would help us a lot.