Google announced nearly two months ago that it was going to begin pushing the Android Wear 2.0 update to existing watches, but since then, few watches have actually been updated. Now we know why.

Google has confirmed that it found a bug during its final testing of the Android Wear 2.0 update, and that that bug has delayed the rollout to most devices. There are a few lucky watches that are now receiving their Android Wear 2.0 updates, though, and they are the Fossil Q Founder, Casio Smart Outdoor Watch WSD-F10, and the TAG Heuer Connected.

Here’s Google’s full statement to Wareable about this Android Wear 2.0 bug:

"We have started rolling out the Android Wear 2.0 update to Fossil Q Founder, Casio Smart Outdoor Watch WSD-F10 and Tag Heuer Connected. For other devices, the update is currently being delayed due to a bug found in final testing. We will push the update to the remaining devices as soon as the issue is resolved."

Android Wear 2.0 brings with it several notable features and improvements, like an on-watch Play Store and a keyboard for message replies. It’s kind of a bummer that most Android Wear watches are still waiting to get their 2.0 update with these features, but it’s better for Google to have found this bug and delayed the rollout so that it can be fixed, rather than Google just pushing the update and then users having to live with the bug while Google works on a fix.