I want to know why releases that look like semver (for example 1.2.3+45) are not marked as semver in Sentry.

Sentry only recognizes a release as semantic versioning (SemVer) when the release name follows the package@version or package@version+build format. For example, [email protected]+45 is recognized as SemVer, while a bare version such as 1.2.3+45 is not.

To fix this, update how you create the release through the CLI, API, or SDK release option so that the package name is included. Avoid adding parentheses to the release name, as Sentry uses them for display purposes only.

If your project still isn't detecting releases as SemVer after updating the format, check your recent releases against the detection rules in the semantic versioning documentation.