Bluetti eb3a AC related short.

Hi there,
I have not used my eb3a in 3 months but, was charged to 100% (always ready for use).
i went to use it the other day but, would not turn on.
I have since learned/applied some troubleshooting which has now allowed me to turn on.
The problem now is, i can ONLY use/charge via DC.
Anything AC related shuts down the unit. I have to wait 5 minutes before being able to power up.

Pressing the AC, plugging in the AC charge plug OR powering a device via AC shuts down the unit.
It seems to be shorting the unit.

PLEASE, any advice would be greatly appreciated.
Thanks.