Set expressions to exclude nulls and count distinct elements not working.

[rmadursk]

I have a set of data that looks like this:

Attested_Date	Service
3/31/2023	satellite01
3/31/2023	wbscvecc11
3/31/2023	wbscvecc11
12/31/2023	rtvspx01
12/31/2023	rtvspx01
6/30/2024	triprh701
6/30/2025	wbscvecm04
6/30/2025	wbscvecm04
12/31/2025	spcsgridn02
12/31/2025	spcsgridn02
12/31/2025	spcsgsub01
12/31/2025	spcsmtier01
12/31/2025	spcsmdata01
-	wbscvemp21
-	wbscvmdm01
-	wbscvmdm01
-	wbscvmgr01
-	wbscvmgr90

I need to know how many Distinct Service names have an Attested_Date.

I've tried the following based on other Community posts:

//Count({$<[Attested_Date] = {"=not isnull([ATTESTED_DATE] )"}>} DISTINCT([Service]))
//Count({$<[Attested_Date] -= "=Null()">} DISTINCT([Service]))
//Count({$<[Attested_Date] = {'*'}>} DISTINCT([Service]))
//Count({$<[Attested_Date] = {"=Len(Trim([Attested_Date])) > 0"}>} DISTINCT([Service]))
//Count({$<[Attested_Date] = {'*'}-{''}>} DISTINCT([Service]))

These all just report back the count of distinct services (14) when it should be 9.

This expression appeared to be working a couple of days ago but stopped for some reason.  I don't think it is the app since I created a new app with just this table and I get the same results.  The Null fields appear to be actual Null fields because they show up in Data Manager Preview Pane as Nulls.

[rmadursk]

I really like this idea. There are several fields/expressions that I think I can use this tactic to make my sheets less complicated.  Just have to remember to do them all before I split and unpivot the troublesome column.