Bug report: Excluding a date doesn't work with in monthly rules

[derdaniel23]

Bug description

If you add an exclusive date in addition to a monthly recurrence rule, it has no effect on the schedule.

Steps to reproduce

Go to co.radiocorax.de, open schedule/4233/ (Corax Night), press Add date, add Date 2020-10-25(26), check the box "Excluding", press "sichern und weiter editieren" , go to the scedule board to the date 25.10.2020

or

Go to co.radiocorax.de, open schedule/4168/ (X-tralight), press Add date, add Date 2020-11-01(02) and so on

Actual result

In the scedule board you find a scedule from "Corax Night" that is not excluded

Expected result

Excluding a date will also work on monthly rules

Workaround

no workaround