Updating Calendar events

I have a calendar linked to a SC source which displays events nicely. It is all tied to a booking system that uses a data store for a Shopping Cart. When adding the event into the cart, I want to adjust the event to show that it has been booked

The dynamic event title is set to:

event-title="'\n'+schedule_productslotname+(ds_cart.data.where('slotoptid',slotoptid,'==').count() ? '\nCart:'+ds_cart.data.where('slotoptid',slotoptid,'==').count() : '')"

(adds the title and, if the product has been added to the cart, the number of bookings found)

which works fine but only after the week/month is moved forwards/back and back to the required week/month. Is there a way to trigger a redraw of the calendar view? The resize option doesn’t seem to do the job for this.

I can use a prev action followed by a next action on the calendar to workaround but seems a bit clunky…