Appsheet Report not using Slice Filter

I have an application that records when an some is referred to us.

Client List
Contains a column with a referral date. Also contains a virtual column [V_Referral_Month] with the objective of identifying if the Month of the Referral is the last month. The formula being

Objective just to return rows that meet the criteria of the Referral Month being last month.
Has a row filter: [V_Referral_Month]=Y

When I preview the Slice with View Data, I get no results returned.
When I create a view in UX, I see the expected three rows.
When I use this Slice to create a report, I get all rows returned, not filtered.

I’m a tad confused as to why I see three different things and why, specifically, the report doesnt see the same as the UX view and reports all records that are in the Client List.
I’m trying to report on only the rows that contain last months referrals.

Do I have to build in a start expressionevery time I use report templates? If so what’s the point of having a Slice filtered?

If you want the report to include multiple rows, yes.

I don’t understand your answer.