Original issue is resolved and we are good there. Other than that issue, end users (majority if not all) will be tabbing into the fields or buttons during data entry. On last 'tab' keystroke, usually focus will move on to the action button and they submit the form by hitting 'enter' or 'spacebar' buttons. At times, accidentally if the user hits 'tab' button one more time (instead of submitting the form), the focus will go back to browser 'Address bar' (not the first field of your screen). So usually it will be a best practice to configure another action-set (Event-> 'Tab Key'; Action -> SetFocus) on the last button to set focus on the first field of your form. This way you are avoiding the in-correct tab focus to browser address bar.

This is another tab focus configuration, which can always be considered for better usability. This will not only address the issue mentioned above, but also keeps the tab-focus within our pega form controls in a cyclic order (rather than taking the focus to browser elements).