I come across a bizarre case. It's for Planning Analytics 2.0.6 but I have seen this in earlier versions too. I never bothered to find out the real cause. Now I do

In my Personal.xlsb I have a macro to open files I use on a regular basis. This macro can be launched by clicking an icon in the QAT (Quick Access Toolbar). This (small) macro uses a second procedure, where a password is asked from the user ( me

Now, opening Excel (therefore opening Personal.xlsb) works fine. Nothing happens initially, until I click the icon, I enter a password and a file is opened. But when I start Perspectives the macro in which the userform is shown also starts. Therefore, anytime I open Perspectives, I also get the question to enter a password to open a file I don't want to open.
How is it possible that opening Perspectives executes a macro in my Personal.xlsb ? It's not even a function but a procedure.
As soon as I have the code to .Show the userform, the macro is eligible for execution whenever Perspectives starts. No other VBA-code / addin is running at all.
I reduced all code to the below. Legend:
1: the icon to launch the macro in Personal.xlsb to open files I use often (macro: 'Open_My_Files' calling a second macro)
2: the userform pops up when I start Perspectives
3: the userform in VBA, nothing fancy
4: the code, reduced to the essential part, issue is still reproducible
5: the code for the userform. Other than a couple of variables, I have nothing there. I could even delete those given that in the Get_Password macro I commented out code as well.
Does anyone have an idea please ?
Happy festivities !
Wim