VBA countif statement only returns 0 - vba

Question

I'm working on a macro that is supposed to count the number of times the term "GM" appears in a column. I decided to use a countif statement, as I have before and it worked well. However, for some reason when I run my code it outputs 0 every time, which definitely is not correct. I've run this same code with other columns and strings and it has worked fine, but for some reason if I search this certain column for the term "GM" it fails. The only thing I can think of is maybe countif only works if the string you're searching for is the only string in a cell, because in all cases where this is true the code works fine. In this particular case the string I'm looking for is not the only string in the cell and the code is failing. I've tried to find more info on whether or not this is true but I can't find anything online. Here's the code if anyone would like to take a look:
Function OemRequest() As Long
Sheets("CS-CRM Raw Data").Select
Sheets("CS-CRM Raw Data").Unprotect
Dim oem As Long
Dim LastRow As Long
Dim LastColumn As Long
'Determines size of table in document
LastRow = Range("A" & Rows.Count).End(xlUp).row
LastColumn = Cells(1, Columns.Count).End(xlToLeft).Column
oem = Application.WorksheetFunction.CountIf(Range(2 & "2:" & 2 & LastRow), "gm")
OemRequest = oem
End Function

Answer 1

You are correct that the COUNTIF as written will only match cells where the whole content is "gm". The criteria in the COUNTIF function will also accept wildcards, so to match on cells that contain "gm" do:
.CountIf(Range(2 & "2:" & 2 & LastRow), "*gm*")
Update
As you noted there is also an issue with your Range call. As it is, the expression inside the parens will evaluate to "22:2<LastRow>" (where <LastRow> is the value of the LastRow variable).
The 2's in there should be a variable containing the column name you're interested in. Something like:
Dim col as String
col = "B"
... Range(col & "2:" & col & LastRow) ...
This will evaluate to "B2:B<LastRow>", which is what you want.

Answer 2

Another possibility:
oem = WorksheetFunction.CountIf(Columns(LastColumn).Cells(2).Resize(rowsize:=LastRow - 1), "gm")
This will count cells containing "gm" (use wilcards if needed) in the LAST column of the table, except the one in the first row. (It assumes the table upper left corner is in cell "A1")
Of course you can create a variable if you would like to count any other column:
Dim lngCol as Long
lngCol = ...
oem = WorksheetFunction.CountIf(Columns(lngCol).Cells(2).Resize(rowsize:=LastRow - 1), "gm")

Answer 3

I think in this way
Sub Main()
Application.ScreenUpdating = 0
Dim Count As Double
Range("C1").Activate 'Firs row in the column
Do While ActiveCell.Value <> ""
If InStr(ActiveCell.Value, "MyText") Then
Count = Count + 1
End If
ActiveCell.Offset(1, 0).Activate
Loop
Application.ScreenUpdating = 1
End Sub
This will work, only if the data cell is not empty, if there is an empty space in middle of the worksheet, do this:
Sub Main()
Application.ScreenUpdating = 0
Dim Count As Double
Range("C1").Activate
Do While ActiveCell.Row <> Rows.Count ' This wil evaluate all the rows in the 'C' Column
If InStr(ActiveCell.Value, "MyText") Then
Count = Count + 1
End If
ActiveCell.Offset(1, 0).Activate
Loop
Application.ScreenUpdating = 1
End Sub
Hope it's work for you.