After a screen replacement, Phone can only turn on without backcover.

I Just replaced my screen on my P10, the phone would blink red while connected to the charger. I removed the backcover and the phone is able to turn on, if I connect up the backcover the phone will turn off.

I suspect I have damaged the battery, If I press down on the bottom left hand part of the battery it will shut down.

Does anyone have any Ideas on this?

Thanks in adavnce !