Watch OS 5.1.1 is out after Apple's earlier update bricked some smartwatches
https://www.cnet.com/news/watch-os-5-1-1-is-out-after-apples-earlier-update-bricked-some-smartwatches/
Watch OS 5.1.1 also includes fixes for Walkie-Talkie and Activity award issues, according to Apple release notes seen by 9to5Mac.
The update should be available now for the Apple Watch Series 1 and later -- but not the original Apple Watch.