Problem key after drained battery BMW F11 --> fixed

Dear BMW drivers,

My german isn't that good so I will try it in english. Hopefully no problemo.

I have a strange problem with my car. Long story short broken timing chain huge costs revision of head of the engine etc ... When the chain snapped I tried starting the cars several times which drained the battery of the car completely. Car was coming up with the message that the remote control wasn't in the car. The car is fixed now and the battery is full.

The strange thing is that one of the keys isn't working anymore. I don't think its coincidence and that this remote is broken during exactly the same time.

When I start up Ista both remotes 1 and 2 are registered and not blocked. It can also measure the voltage of the not working remote but it won't communicate with the car. It only starts the car when I place the remote near the coil. The other key is working perfect as with comfort access and al the buttons.

Is there an additional way of testing this not working remote? Can one of the remotes after completely draining off the battery of the car be disconnected / unregistered somehow? Or do I need something like an ACDP tool to readout the CAS4 / 4 + via OBD. The BMW dealer couldn't directly fix the problem so I needed an appointment and I assume that they are gonna charge a lot of money.

Hopefully someone has any idea.

Thanks in advance!

Ps. I changed the battery of the key and switched them around with the two keys no success

See screenshot the second column also gets green until 50% when using the not working key thus somehow they are communicating.

Fixed it :D. It was thinking why not a good old reset so I pulled the negative terminal of the battery waited a minute and connected the battery again. Problem fixed. Really strange! Hopefully it will help somebody!