Still getting desktop notifications about new mail even after logging out of outlook

I use outlook for my personal and my office mail. Outlook asks for destop notification permission for new mails. I had them allowed for new mails. But i noticed that even after i log out my account, i get desktop notifications for my mail. Is outlook still logged in even after i hit sign out ? Is firefox still connected to the outlook even after i log out. Also i cant confirm if this issue is outlook based or due to firefox , coz i dont use any other browser so i cant confirm. Please check as this is a serious privacy and security issue and can potentially be exploited.