Can't get seacret valiables only when run with PR triggers

[maiko.morisaki.ub]

Use ‘Bitrise Start Build’ to execute multiple workflows from a single trigger.
If PR is triggered and executed, it will fail because it cannot get the value set in the Bitrise Access Token.

access_token: <unset>

Succeeds when executed from Slack or manually.

Is this a bug? Or is the specification that triggering from PR does not work?

Thanks for your help.

[pilvikala]

Is your secret set to be exposed for pull requests (see the red switch under the value for the secret)?