Jesus - has it been like that for everyone since the migration?
I've made a change and will mention you in the next non-reply post. Let me know if It works...
It does for me (screenshot below).
Everyone configures their own notifications in their preferences (direct link here: https://www.northstandchat.com/account/preferences) - scroll down to "Receive a notification when someone..." and check where required. Remember to click save when done.