I have had a brief look at your code - it is quite unconventional and I am not surprised that you are having trouble. I mention some of the things that I think are causing problems below. I guess that you must have written code in this style before but I never have, so I probably cannot help you much.
Here are some of the things that I find unusual and likely to cause trouble ...
1. You have executable code in Sub Globals. This is not normal (it is intended only for declarations) and may well be causing effects that you do not expect.
2. In Sub Activity_Create you have this code :
If FirstTime = False Then
Return
End If
I don't know what you are trying to achieve, but I suspect that what is happening is not what you think is happening.
3. In Activity_Create you have references to what I assume is a class (GlobalFunctions) in the following form ...
If GlobalFunctions.aryMasterList.IsInitialized = False Then
GlobalFunctions.Popup_Query_Message = "Nothing to show."
Activity.Finish
Return
End If
Again, trying to close an Activity before Activity_Create has finished is something that I have never attempted but I would expect to lead to problems. Also, putting "Return" after "Activity.Finish" does not make sense.
4. Sub Activity_Resume is entirely missing from this code.
The best suggestion I can make is that you look at some coding examples and tutorials and try to follow a more standard code structure. Also if you want anybody else to give advice then post your complete project ("Export as Zip"). It might be a good time to start using B4XPages.