Appflow expects app versions to follow the NPM semver standard. This standard does not allow for leading zeroes before any other digit. Apps with an invalid version will fail the check for updates with a 422 error.
1.0.3 = valid
1.0.03 = invalid
0.0.50 = valid
0.0.050 = invalid
To resolve the issue simply correct the version and prepare a new native build.