Google’s last two Nexus-branded smartphones, the Nexus 5X and Nexus 6P, are both suffering from connection difficulties when attempting to be used with in-car Bluetooth kits. The issue is causing problems for the two devices after being updated to Android 7.1.1 Nougat and appears to cause problems with many different car kits. Google were first notified of the issue back in October 2016 with the release of the Android 7.1.1 Nougat developer preview, but to date the issue has not been resolved, even with the January security patch installed. There appears to be a similar issue with the Google Pixel and Google Pixel XL devices, but fewer customers have reported a problem here. This may be because there are fewer Google Pixel devices in circulation or because it is less of an issue.
The issue manifests itself in a number of different ways, including, the handset will connect to the device for between one to six seconds before disconnecting. Some customers report that the device works as it should and will stream music over the media connection, but after a call is concluded the device will disconnect from the Bluetooth kit and has to be manually reconnected. Other customers report interference on the line or the device disconnecting from the Bluetooth car kit mid-way through a conversation. However, those affected customers report that there does not appear to be an issue when connecting the Nexus 5X or Nexus 6P to a wireless Bluetooth-enabled speaker or, in at least one case, a motorcycle hands free kit. Naturally, that the issue has persisted from the first developer preview, into the production builds and has survived the January security and bug fixing patch, some customers are frustrated that these Bluetooth issues persist. One customer went to the length of flashing a custom ROM, based on Android 7.1.1 but using the radio firmware from Android 7.0 and discovered that with this combination the Bluetooth radio still worked as expected - although this may have been the custom ROM being used. Although unverified, it would appear that Google introduced a Bluetooth bug with the changes to the device radio when updating Android to 7.1.1 Nougat.
Although Google does seem to have recognized the issue, they have not provided any information as to when the issue might be resolved. It is possible that a fix will be issued with the February security patch, due out in a few weeks, or perhaps users will need to wait for the update to Android 7.1.2 Nougat update.