Schedules won't start for certain Branches

Schedules wont start for some branches

gitlab-version: gitlab omnibus 12.9.0

we have one Project where schedules are not created for “master” and “Staging” branche.
while schedules run fine on new branches.
also regular pipelines work without problem.

if i create a new “test-branch” from staging (without changing anything)
i am able to run schedules from this branch.
if i try to run the schedules on staging or maste, no pipeline is created.

i am Project owner so i should be ale to run these schedules without problem, also it does not seem to matter if the branch is protected or not.

i suspect something “strange” in that repository. as this a relativly old project. it has seeen alot of gitlab versions. so maybe at some point the configuration broke.

Gitlab-ci configuration

our .gitlab-ci.yml is quite complex. (and actually mutiple files with multiple includes. so i avoid posting the full version here. but i created a rather simple test job. (without depenacies to test this behavior)

"test job":
  image: alpine:latest
  stage: build
  tags:
    - docker
  script:
    - echo "test"

Trouble shooting so far:

  • tried to unprotect branches.
  • changed owner of the scheduels
  • created most simple job to avoid depencies / constraints
  • looked d the gitlab logs wher it seems that the schedule is created and imidietly marked as done. (whithout ever creating a pipleline in the pipeline view)

Thanks for your time i hope you could guide me on how to debug this issue further. to see if its something strange in the git repository or a bug in gitlab-ci