finish other activity

hi I need if the user in the current activity changes the theme of the Application, close the previous activity and run it again, the following code works on most phones but does not work on some Android 10+ phones, is there an alternative has it? Dim Jo As JavaObject...

If I browse from main to Activity2 and then Activity3 the back key returns me to A2, then main (unless I have finished them after calling sub-Activity what I do not want here). If I want a button on Activitiy3, which finishes the hole app: how is this easyly achieved? should I call sub on A2...