Problem with parameters on jobs REST API endpoint

When I use the REST API /jasperserver-pro/rest_v2/jobs to set off a job immediately using a simpleTrigger, the report parameters are set as expected.
However when I schedule the same report using calendarTrigger to run e.g. monthly, the parameters seem to be ignored on the saved job.
I tried to set the attribute allowExtraReportParameters to true already. This does not seem to change anything.

Can anyone help please?

Regards,
Stian