code not working when moving command button to different sheet

Hi There , I have the below code which works perfectly fine. The command button was first placed on the "Summary_Maint_List" sheet. I then created a User Landing Page (UI) called "UI_Annual_Planner" and copied the command button there so that the code can be activated from the UI page.

I also included a small code at the bottom (red) that un hides the Maint_List_Sheet and it opens that sheet.

The problem is, now that i have copied the command button to the UI sheet the code no longer works, when I copy it back to the Summary_Maint_List it works fine

does anyone know why that happens

Sub datesexcelvba()
    Dim myApp As Outlook.Application, mymail As Outlook.MailItem
    Dim mydate1 As Date
    Dim datetoday1 As Date
    Dim x As Long
    lastRow = Sheets("Summary_Maint_List").Cells(Rows.Count, 1).End(xlUp).Row
    '<<<<<<<<<<<<<<<  Clear  <<<<<<<<<<<<<<<<
    Range("Maint_Summary[[Reminder 13]:[Days Difference 14]]").Clear
    '<<<<<<<<<<<<<<<<<<<<<<<<<<<
    DaysToAdd = Weekday(Date)
    If DaysToAdd > 2 Then DaysToAdd = 0
     
 datetoday1 = Date
   For x = 5 To lastRow
             
If Cells(x, 11) <> "" Then
 mydate1 = Cells(x, 12).Value

If ((mydate1 - datetoday1 <= 30) And (mydate1 - datetoday1 >= 30 - DaysToAdd)) _
                     Or ((mydate1 - datetoday1 <= 2) And (mydate1 - datetoday1 >= 2 - DaysToAdd)) Then

            Set myApp = New Outlook.Application
            Set mymail = myApp.CreateItem(olMailItem)
           mymail.To = Cells(x, 7).Value
            With mymail
                .Subject = "HSE - Maintenance Reminder"
                .Body = Cells(x, 6).Value & " " & Cells(x, 8).Value & " " & Cells(x, 12).Value & vbCrLf & "The above maintenance/revision is due on the specified date. " & vbCrLf & "Please inform your Regional HSE Advisor once completed and kindly upload the new record in your plant HSE folders on the N drive. " & vbCrLf & "Should you require any assistance please contact your Regional HSE Advisor, " & vbCrLf & "Kind Regards."
                .Send
            End With
            Cells(x, 13) = "Yes"
            Cells(x, 13).Interior.ColorIndex = 3
            Cells(x, 13).Font.ColorIndex = 2
            Cells(x, 13).Font.Bold = True
            Cells(x, 14).Value = mydate1 - datetoday1
        End If
End If
    Next
    Set myApp = Nothing
    Set mymail = Nothing
    
    With Sheets("Summary_Maint_List")
        .Visible = True
        .Activate
    End With
End Sub

lol,hi Sintek, I know I'm a sinner sorry I forget these things sometimes

I found the problem tough , because the sheet itself has a very hidden code on the sheet itself the code did not run

so i took

 With Sheets("Summary_Maint_List")
        .Visible = True
        .Activate
    End With

and placed that at the begging of the code making the sheet visible first before running the rest of the code