Multiple Invites per Rota Duty received via Service Scheduling Matrix

I recently tried using the Service Matrix to plan and assign rota duties, instead of working through Services individually. We have 4-5 different service types depending on the Sunday in the month, so could only do one Service Type at a time (have raised this as a request separately to be able to select more than one)

After I had completed each Service Type for the Quarter (Jan to Mar), I selected Send All Invites. It summarised the dates and amount of invites which would be sent for each and I then confirmed to send.

I repeated this for each Service Type.
Unfortunately, multiple Invites were received by rota volunteers for each rota duty assigned. I myself received 4 requests for 1 reading on 1 Sunday from 1 service Type!
It appeared to send/re-send invites for everyone across the service types.

Is this a Glitch/Bug? When Send All Invites is selected, does it also resend invites where no response yet received for other Service Types?

I'm struggling to understand what happened here, and will go back to scheduling rota duties via each service separately for now, as don't want to clog up the volunteer inboxes!!

Thanks!