The version on Google Play is 5.5.1 https://play.google.com/store/apps/details?id=io.particl.copay
While latest git tag ang github release are for previous 5.5.0 version
https://github.com/particl/copay/releases/tag/v5.5.0
Looks like code for this version exists in ratefix branch instead: https://github.com/particl/copay/tree/ratefix as the master branch contain code up to 5.5.0 version.
Make a new github release for the latest version, and push the commits to master branch as well.