When I updated my P4P, Devices stopped connecting. Red LED on the receiver, purple LED on the transmitter. I tried C1, C2, shutter, nothing.https://youtu.be/9EPHQA3uhts
https://youtu.be/1B52XJeEzpk

https://youtu.be/9EPHQA3uhts

Hi, Grzes92. Thanks for reaching out and posting your concern. There might be an update error or an error with the RC program. We recommend that you reset it. To reset the remote in this state, power off the remote controller, then press and hold the C1 and shutter button at the same time. Power on the remote controller and a self-check will be performed. Then there will be a firmware update prompt shown in the app. Download the firmware and update it. Then restart the remote controller.

DJI Gamora Posted at 2-28 23:00
Hi, Grzes92. Thanks for reaching out and posting your concern. There might be an update error or an error with the RC program. We recommend that you reset it. To reset the remote in this state, power off the remote controller, then press and hold the C1 and shutter button at the same time. Power on the remote controller and a self-check will be performed. Then there will be a firmware update prompt shown in the app. Download the firmware and update it. Then restart the remote controller.

not responding

Grzes92 Posted at 3-1 11:36
not responding

We're sorry to read about that. Since the same problem persists, we strongly advise returning your product back to our Service Center for further diagnosis. At your soonest convenience, please get in touch with our Customer Support to assist you to open a ticket.

The purple light on you remote is cause by a failed firmware upgrade, which can happen some times. This is fairly tricky to solve since technically your remote is now bricked and will most like not respond (as you've already mentioned) or allow any updates.
As Gamora said it's the best to send it in to tapply for an RMA and if you still have warranty it will most like be fixed or replaced without any cost.