Slicer not Showing correct Entries (USERELATIONSHIP measure issue)

I have an annoying issue that I need help with...🤔

So I have a model with deliveries by date and supplier and reference, these are then collated into production batches.

I have a calendar table that is linked to the Production date, with an inactive link back to delivery date.

Want a report, with a single relative date filter, two tables that operate on that date filter to show in that date range for deliveries, and production.  No problem, as I can use a measue with USERELATIONSHIP to operate using the inactive date relation ship, all good. 

I hit a problem when I want a slicer on that report page by supplier, what the slicer is asking, show me the deliveries by that supplier on the current deliveries table.  But the date filter is filtering the slicer items, the suppliers in the table are not the same as in the slicer.

Note, I've made up an example file, in the real file I have 10 years of deliveries, and 1000+ suppliers, so cannot edit relationships to turn off the date filter, as the slicer would have 1000+ entries.  Slicer needs to show the suppliers with deliveries in that date range

Sample file link below, and images...

Many thanks for help.  Have a good weekend when it come to you

Stay safe and well

Paul

https://1drv.ms/u/s!ApcyZzyFx2-9hZRgrJD__Iw1U1MC2w?e=6M25WN