How does semantic versioning work?

I’ve just done a new release to our customer and manually uploaded the version with:
sentry-cli releases new -p myproject 0.0.53
sentry-cli releases --org mycompany deploys 0.0.53 new -e beta

0.0.53 shows up in the Releases list. It’s top of the list of releases sorted by Semantic Versioning. But the list sorted by Build Number shows “There are no releases
with semantic versioning”:
https://sentry.io/organizations/mycompany/releases/?sort=build

If “0.0.53” isn’t semantic versioning then what is?