Why is my azure pipeline cron job not running?

Question

I'm trying to get a cron schedule running by using yaml instead of azure pipeline scheduling.

This is my YAML:

trigger: none
pr: none
schedules:
- cron: "0 0 * * *"
  displayName: Daily midnight build when changes have been pushed
  always: true
  branches:
    include:
    - branch1
    - branch2
variables:
- group: BranchVariables

First it ran every time someone made a PR, figured out that I've to add "pr: none". Now I don't know what is missing. What am I potentially missing? The ms documentation is sparsely and I already read all the related topics on this issue.

Thanks in advance!

Update: When I want to check the schedules on the pipeline it doesn't show me any and I can't sync

When I edit the pipeline I get the current yaml version on master branch we do not use anymore and is not the default branch. The pipeline should only run for the two branches I include in the yaml branches property.

The pipeline still didn't run this night and my guess was now that the yaml with the schedules must be also checked into the master branch. I figured out that the default branch can be set for every pipeline and I changed it now and finally can sync and see the schedules. What's still mysterious to me is that I had to add the default pipeline branch to the included branches before the schedules showed up. I'm now using only one included branch.