Question:
Why does the shop notifications don't work?
Answer:
Please note that messenger notifications will only work if the user purchased from your store through messenger.
To enable this, you have to create a messenger chatbot flow then add a button that uses Ecom Urls. For the admin, you must subscribe to MMIO messenger notifications.
Go to My Account → Notifications → Subscribe
As for the shop notifications, try to clear your Messenger App cache. Try using another mobile phone/device to do a test purchase, as well.