Find first instance of the acronym - vba

Question

Any help would be awesome. I have a macro that finds acronyms and applies a spell out of the acronym with the acronym in parenthesis. It is applying the spell out and acronym once but randomly. I need the macro to identify the first instance and apply the spell out only to that first instance. So if the first instance should look like this:
Be Right Back (BRB) some text BRB some text BRB
Right know it looks like this: BRB some text Be Right Back (BRB) some text BRB
The macro has the code " .Execute Replace:=wdReplaceOne" but it doesn't seem to be working.
Here's the code I am using:
Sub AcronymManager()
Application.ScreenUpdating = False
Dim FRDoc As Document, FRList As String, j As Long, StrExp As String, StrAcc As String
'Load the strings from the reference doc into a text string to be used as an array.
Set FRDoc = ThisDocument
'Alternative code to use a different document the reference doc:
'Set FRDoc = Documents.Open("C:\Users" & Environ("UserName") & "\Documents\AcronymList.doc")
If ActiveDocument = FRDoc Then
MsgBox "Error: Cannot process this document - it's the source document", vbCritical
Exit Sub
End If
FRList = FRDoc.Range.Text
If FRDoc <> ThisDocument Then FRDoc.Close wdDoNotSaveChanges
Set FRDoc = Nothing
With ActiveDocument.Range.Find
.ClearFormatting
.Replacement.ClearFormatting
.Replacement.Highlight = True
.MatchWholeWord = True
.MatchCase = True
.Wrap = wdFindContinue
'Process each word from the Check List. Tab-delimited strings are assumed, formatted as:
'Find text <Tab> Replace text
For j = 0 To UBound(Split(FRList, vbCr)) - 1
StrExp = Split(Split(FRList, vbCr)(j), vbTab)(0)
StrAcc = Split(Split(FRList, vbCr)(j), vbTab)(1)
.Text = StrExp
.Replacement.Text = StrAcc
.Execute Replace:=wdReplaceAll
.Text = "(" & StrAcc & ")"
.Execute Replace:=wdReplaceAll
.Text = StrAcc & "^w" & StrAcc
.Execute Replace:=wdReplaceAll
.Text = StrAcc
.Replacement.Text = StrExp & " (" & StrAcc & ")"
.Execute Replace:=wdReplaceOne
Next
End With
Application.ScreenUpdating = True
End Sub