Webhooks suddenly stopped working when multiple branches pushed at once

Summary

If I push multiple branches to a repository at once (eg git push origin branch1 branch2 branch3), no webhooks fire. This is new behaviour, as previously the webhook would fire for all three branches.

Steps to reproduce

1. Create a webhook that is triggered by PUSH events (make sure it applies to all branches - no filters)
2. Push to one branch (eg git push)
3. Observe that the webhook fires
4. Push to multiple branches at once (eg git push origin branch1 branch2 branch3)
5. Observe that no webhooks fire at all

Example Project

Private repository - https://gitlab.com/settify/webapp/hooks/312877

What is the current bug behavior?

No webhooks are fired when multiple branches are pushed at once

What is the expected correct behavior?

Webhooks should be fired for all branches that were pushed

Relevant logs and/or screenshots

N/A

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

This bug happens on GitLab.com

Results of GitLab application Check

This bug happens on GitLab.com

Possible fixes

I don't know where to start, sorry 😢