AirPods, are not perfect at this point. Apple has started its investigation to fix the bug in Airpods that leads to the problem of call disconnection. Some users have also experienced audio problems, including the synchronization of each wireless earpiece.
According to MacRumors, Apple is investigating a disconnection issue with Airpods when making a call. Users report that AirPods disconnect at the time of the call, while they are working properly when listening to music or other activities. According to the first feedback, the users concerned are those who have an iPhone 6s or an iPhone 6s Plus, accompanied by an Apple Watch or a connected bracelet.
Users tried to remove the pairing between the iPhone and the AirPods, and then connect again to see if the problem still existed. Indeed, nothing changes and the disconnection is always present during calls. Restarting the iPhone does not change anything. A temporary solution seems to have been found and it is not the most ideal: use only one of the AirPods at the time of a call. The disconnection seems not to be topical here.
Hopefully Apple will quickly find a solution and offer an update for users. If you are concerned, contacting Apple may possibly be a solution to attempt and have a replacement pair.