Google’s Pixel smartphones are two of this year's greatest handsets, offering the best Android software experience yet. The many excellent early reviews resulted in Google underestimating demand for the devices, but it seems they’re not without their issues.

First came reports that purple shade and random artifacts were affecting some Pixel users’ cameras. This was followed recently by claims that the handsets’ audio can distort when played at maximum volume within certain apps. There have also been reports of LTE connectivity problems.

But the latest problem - discovered on Google’s product forums by Android Police - appears more serious. Since November, there have been numerous reports of Pixel phones suddenly freezing and becoming unusable. On some occasions, the navigation buttons disappeared. The handsets can stay in this state for a few seconds to several minutes.

It was thought that third-party apps like Life360’s Family Locator were causing the freezes - some users of the GPS tracking application found uninstalling or disabling it fixed things. But others who haven’t installed that particular piece of software have also run into the same problems, so it seems the source of the issue is unclear. Many reports say it appears to occur randomly, and one user even said it happened when the phone wasn’t in use.

Both Pixel and Pixel XL owners have reported their handsets randomly freezing, suggesting a common hardware problem. Clearing the cache or performing a factory reset isn't helping things, either.

Google has yet to make a statement regarding the issue, and it’s unclear exactly how many owners have been affected.