On Catering > Proposal Settings > Recurring, flip the Status switch on the schedule's row to off (or open the schedule and untick Is Active? then Save) — inactive schedules are skipped by the daily job. To end it on a date, open the schedule and set Ending Date to a specific date. To remove it entirely, open it and click DELETE ("Are you sure you want to delete this recurring proposal?"). Proposals already generated are not affected.