I created a test project to sync tags with a github project, and jobs can be triggered by pulled tags. Please create a test project here to see if it can be reproduced.

I pushed the project that I have the issue with: https://code.onedev.io/test-mirror2 As you can see the tags got pulled but that did not trigger the build job.

This happens as tag commit does not define any OneDev jobs. When pull tags, OneDev checks each tag commit to see if it contains OneDev build spec, and if yes, it continues to check each defined job to see if the trigger applies. Job defined in main branch does not apply for tags.

This is designed to be so to make sure that behavior (OneDev job definitions) and data (commits the job runs against) are always from same commit.