Slice filters correctly but Select() pulls filtered out rows?

[PhilTheThrill]

I am working on an app that compares rows in one sheet (S1) to rows in another (S2) looking for mismatches. I created a Slice (called Mismatched) on S1 that only shows rows from S1 that mismatch. It works perfectly. 

In S2, I want to have an expression in a virtual column that just marks whether that row appears in the Mismatched Slice. 

in([_THISROW].[TimeCardID], select(Mismatched[ID],true))

Here's the problem: that select statement is pulling ID numbers that do not appear in the Slice when I view it. The Slice view shows maybe 30-40 entries but the select statement appears to be pulling everything from S1. Like in two monitors I can literally see side by side that ID number "523775" does not appear in the Slice but the expression comes back "Hey I found 523775 in there!"

As near as I can tell, the Select() is able to reference the Slice but it's not respecting that slice's filter? Is that possible? Am I high? Any ideas?

[SkrOYC]

First, try without the SELECT(), just making a list by using "Mismatched[ID]".
Now, that shouldn't be a solution, if it is it means there is a bug.

Also, make sure that you are absolutely correct about the expression you are using to filter rows in your slice, maybe it's an expression that actually evaluates rows in ways that you don't expect. Remember that a slice is always changing, it's not like a security filter