I would try the following
- Try Factory reseting the phone that has the side car attached to it. This should make the phone re-download the firmware and config. This should hopefully fix the issue.
- If you have a Spare side car, replace the existing one with a spare known working side car. If the behaviour is not same with the new spare side, car then we know we have a defective side car. You could RMA it.
- It the behaviour is same with the spare side car, then we are dealing witha software issue. I would open up a TAC case for this.