Problems using Provider=OraOLEDB.Oracle via VBScript/Classic ASP

Okay, background: existing Oracle db running on linux. I've taken over the creds for it.

I am looking to develop some basic (classic) asp pages to show some reporting info for Management, and seem to have hit a snag...

So far:
Installed SQL Developer. All test SQL queries work and provide the expected response!
At this stage using my local machine as dev, so installed the relevant 64 bit tools and drivers from the Universal installer.
Looking in ODBC (just to check), I have 64 bit "Oracle in OraClient 11g_home1".

Test 1:
SQL Developer

SELECT STAFFID, STAFFNAME FROM T_STAFFINFO WHERE STAFFNAME IS NOT NULL ORDER BY STAFFNAME asc;

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Works perfectly

VBScript

Option Explicit

Dim isDebug, asp
isDebug = True
asp = 0

Dim strSQLQuery
strSQLQuery = "SELECT STAFFID, STAFFNAME FROM T_STAFFINFO WHERE STAFFNAME IS NOT NULL ORDER BY STAFFNAME asc"

Dim strDBDesc
strDBDesc = "(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=1.2.3.4)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=mySVC)));"

Dim strUserID: strUserID = "myUser"
Dim strPassword: strPassword = "myPass"

Dim ADODBConnection
Set ADODBConnection = CreateObject("ADODB.Connection")

Dim ADODBRS
Set ADODBRS = CreateObject("ADODB.Recordset")

Dim strConnection
strConnection = "Provider=OraOLEDB.Oracle;Data Source=" & strDBDesc & _
                "User ID=" & strUserID & ";Password=" & strPassword & ";"

DebugOut "strConnection = " & strConnection & vbCrLf

ADODBConnection.Open strConnection
Set ADODBRS = ADODBConnection.Execute(strSQLQuery)
Set ADODBConnection = Nothing

If Err <> 0 Then
    DebugOut "An error occurred in Opening Connection: " & Err.Number & " " & Err.Description & " " & Err.Source
Else
	
	ADODBRS.MoveFirst
	Do Until ADODBRS.EOF
	
	DebugOut ADODBRS("STAFFID") & vbTab & ADODBRS("STAFFNAME")
	ADODBRS.MoveNext
	
	Loop
End If


Sub DebugOut(sText)
	If IsDebug Then
		If asp=1 Then
			Response.Write Now() & vbTab & sText
		Else
			WScript.Echo Now() & vbTab & sText
		End If
	End If
End Sub

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Also works perfectly. Rejigged that to classic .asp and put it behind IIS7.5 - works peachy as the first page, a drop down with all staff populated

Test 2
SQL Developer

SELECT to_char(ACTBEGIN, 'DD-MON-YYYY') as WORKDATE,
MIN(to_char(ACTBEGIN, 'HH24:MI:SS')) AS STARTTIME,
MAX(to_char(ACTEND, 'HH24:MI:SS')) AS FINISHTIME
FROM T_ATTENDANCE
WHERE STAFFID = 1
AND ACTBEGIN BETWEEN '01-OCT-16' AND ADD_MONTHS('01-OCT-16', 1)
GROUP BY to_char(ACTBEGIN, 'DD-MON-YYYY')
ORDER BY WORKDATE;

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Works just fine

VBScript

Option Explicit

Dim isDebug, asp
isDebug = True
asp = 0

Dim strSQLQuery
strSQLQuery = "" & _
"SELECT to_char(ACTBEGIN, 'DD-MON-YYYY') as WORKDATE, " & _
"MIN(to_char(ACTBEGIN, 'HH24:MI:SS')) AS STARTTIME, " & _
"MAX(to_char(ACTEND, 'HH24:MI:SS')) AS FINISHTIME " & _
"FROM T_ATTENDANCE " & _
"WHERE STAFFID = 1 " & _
AND ACTBEGIN BETWEEN '%SDATE' AND ADD_MONTHS('%SDATE', 1) " & _
"GROUP BY to_char(ACTBEGIN, 'DD-MON-YYYY') " & _
"ORDER BY WORKDATE"

Dim strDBDesc
strDBDesc = "(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=1.2.3.4)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=mySVC)));"

Dim strUserID: strUserID = "myUser"
Dim strPassword: strPassword = "myPass"

Dim ADODBConnection
Set ADODBConnection = CreateObject("ADODB.Connection")

Dim ADODBRS
Set ADODBRS = CreateObject("ADODB.Recordset")

Dim strConnection
strConnection = "Provider=OraOLEDB.Oracle;Data Source=" & strDBDesc & _
                "User ID=" & strUserID & ";Password=" & strPassword & ";"
				
DebugOut strConnection & vbCrLf
DebugOut strSQLQuery
				
ADODBConnection.Open strConnection
Set ADODBRS = ADODBConnection.Execute(strSQLQuery)
Set ADODBConnection = Nothing

If Err <> 0 Then
    DebugOut "An error occurred in Opening Connection: " & Err.Number & " " & Err.Description & " " & Err.Source
End If

	'ADODBRS.MoveFirst
	Do Until ADODBRS.EOF
		DebugOut ADODBRS("WORKDATE") & vbTab & _
		ADODBRS("STARTTIME") & vbTab & _
		ADODBRS("FINISHTIME") & vbCrLf
		ADODBRS.MoveNext
	Loop


Sub DebugOut(sText)
	If IsDebug Then
		If asp=1 Then
			Response.Write Now() & vbTab & sText
		Else
			WScript.Echo Now() & vbTab & sText
		End If
	End If
End Sub

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I get no output (apart from the test lines). If I uncomment out the ADODBRS.MoveFirst I get the dreaded ADODB.Recordset: Either BOF or EOF is True, or the current record has been deleted

So......
SQL Developer the SQL works fine
VBScript/Classic ASP a simple SQL query using the standard ADODB methods works fine
A more complex SQL query which works fine in SQL Developer returns no data when ran in VBScript using exactly the same connection strings as in the simple query

What am I doing wrong?????

I'll give 500 points to whoever fixes me