You can't use "AND" for naming multiple table field names, the separator is a comma.
Code:
Sub modque_addnewlocation() ' update query Dim db As DAO.Database
Dim db As DAO.Database
Set db = CurrentDb
Dim dateDate As Date, strLineNo As String, strSQL As String
Dim strSvc As String, lngProposalNo As Long
dateDate = DateValue("9/27/2025")
strLineNo = "104"
strSvc = "stripe"
lngProposalNo = 20250537
strSQL = "UPDATE tblCalendar SET fLngProposalNo = " & lngProposalNo & ", " _
& "fTxtService = '" & strSvc & "'" _
& " WHERE DateValue(fDate) = #" & dateDate & "# AND fStrLineNo = '" & strLineNo & "'"
Debug.Print strSQL
db.Execute strSQL, dbFailOnError
End Sub
Immediate Pane: shows debug.print
call modque_addnewlocation
UPDATE tblCalendar SET fLngProposalNo = 20250537, fTxtService = 'stripe' WHERE DateValue(fDate) = #9/27/2025# AND fStrLineNo = '104'
Result: