And if you already have, then just try toggling the notifications settings, which means turn off and on the notifications, sometimes these kind of tricks also works.
Ummm…Then i would request you to reach out to you HubSpot Support.
You have the access to Reach-out to support if you are on any paid license.
Navigate to the Question mark sign in the top Right https://prnt.sc/rU2CnHrl-1Q_ > click on contact support in the bottom right > A support will help you solve this.
As they have the access to your portal, so they will be the best people to assist.