Google suspends the rollout of Wear OS 5 on the 1st and 2nd generation Pixel Watch. Users are reporting that the update causes their watches to lock up. This was reported by The Verge.
The blocking is not permanent. The Google support site has some general troubleshooting steps. In addition, the manufacturer has published instructions on how to reset the watch to factory settings with Fastboot if you cannot access the normal settings.
Google plans to resume rolling out Wear OS 5 to older Pixel Watch models after fixing the bug "later this year."
By the way, Google has added one new feature for all Pixel Watches that doesn't require Wear OS 5. The watch will now send notifications to the user's smartphone when it is fully charged.