Now that we have your sheet working the way you want. I would like to introduce you to some advanced Programming Practices.
Any Event Sub can only have one instance, so you cannot have, say, one Change Event for H46 and a different Change Event sub for another Range. IOW, the one Event sub must handle that Event for all Ranges, no matter if all Ranges get a different treatment.
I have seen may Event subs so overloaded that one could not decipher what was going on and the Writer could not make the Sub works properly. One solution for that is to write Event Subs so that their only task is to determine which Range the Event occurred at.
For example
Private Sub Worksheet_Change(ByVal Target As Range)
If Target is (A1) THen MakeNegative Target
ElseIf: Target is A2 then MakePositive Target
EsleIf: Target is A3 THen MakeRed Target
ElseIf: Tegrat is A4 then MakeBlue Target
End IF
End Sub
As you can see, the Event sub is neat, concise, easily edited and easy to make right. If there is any problem it will be in a separate and simple Sub or Function that only does one task.
Refactoring your code to use this Pattern does seem a bit more complicate and bulky, but it also means you can add to the actual Event sub with no issues of code interference.
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, JV_EX) Is Nothing then MakeNegative Target
ElseIf: Not Intersect(Target, TotalRemit) Is Nothing then MakeNegative Target
'ElseIf: Some Other Range... Do something different
End If
Application.EnableEvents = True 'Redundant, but Just In Case
'all subs that do something to the worksheet should set and reset EnableEvents
End Sub
Private Function JV_EX() As Range
'Note: By setting the ranges for the Event sub in separate Functions, If you ever
'modify the Worksheet, you only have to edit the Set Ranges Functions. It also keeps
'the Event Sub neat and concise.
Set JV_EX = Range(Range("E7"), Cells(Rows.Count, "A").End(xlUp).Offset(0, 5))
End Function
Private Function TotalRemit() As Range
Set TotalRemit= Cells(Rows.Count, "H").End(xlUp).Offset(-1, 0)
End Function
Private Sub MakeNegative(Target As Range)
If Not IsNumeric(Target) Or Target <=0 Then Exit Sub
Application.EnableEvents = False
Target = Target * -1
Application.EnableEvents = True
End Sub