Group hook push event branch filter does not apply
Summary
I have a group webhook at https://gitlab.com/groups/whisperfish/-/hooks, with "push event" enabled. I have tried setting the branch name/wild card pattern for filtering, which used to work on the project-level.

The setting is "accepted", but upon clicking edit, the input field is empty again.
I'm quite sure that I had filed the webhook filter from the beginning, but it was not applied either.
Steps to reproduce
- Create a group webhook with push event enabled.
- Edit group webhook
- Try to apply a filter to the push event (e.g. "master" in our case).
- Edit again
- Notice the text field is empty.
After 3, we notice the hook does indeed not filter.
Example Project
https://gitlab.com/groups/whisperfish/-/hooks triggered through https://gitlab.com/whisperfish/whisperfish
What is the current bug behavior?
The webhook triggers a push event for any branch on any project.
What is the expected correct behavior?
The webhook filter gets installed, shows when edit is pressed, and correctly filters based on branch name.
Relevant logs and/or screenshots
This is a rebase + force push on groupv2 branch, which should have been filtered out. The webhook goes to our Matrix bot:
Output of checks
This bug happens on GitLab.com
Results of GitLab environment info
Expand for output related to GitLab environment info
(For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)
Results of GitLab application Check
Expand for output related to the GitLab application check
(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)(we will only investigate if the tests are passing)
