Reproduction steps on my side:

1. new item
2. project name "test-parameterized-scheduler"
3. Check "This project is parameterized"
   1. name: some_string
   2. Default Value: some_value
4. Save job
5. Configure job again
6. Check "Build periodically with parameters"
   1. Schedule:

      * * * * * % some_string=blah

1. Build section
   1. Execute shell

      echo "testing"

1. Save

Job never fires off

Please let me know what log files you may need. I don't think I can submit a support bundle outright, as it would contain our hostnames in our private organization.