"X" is not a valid row reference for filtered crossdoc table

I have a doc that is CrossDoc’ing in two tables, A & R. Table R has a column RA that is a multi-select lookup-type column of A.

A is a large table, and R only requires 30% of the rows, so due to size considerations I CDoc in a filtered view of A, AThird.

The problem is that Coda does not recognize AThird as the ‘original’ table A that R references, so this provides the ‘Not a Valid Row Reference’.

When there is a single value in RA, I can ‘hack’ the problem with

The problem is when there are multiple values in RA. I have tried to use ToText() with ParseCSV() to generate a list of values in RA and then find them with Contains(). I can’t get this to work.

Any ideas on how to adjust my schema, lookups or formula to get the values to match?