Laggy and broken notifications

Ive used Gmail for a long time. Ive noticed that lately- past several months Ive been seeing a notification and the email isnt in my inbox. Sometimes it shows up --and sometimes it doesnt. When I log in on my laptop I see all the missing emails. This has been particularly frustrating as I rely on email in a number of situations as the sole method of communications. If this doesnt get changed I will be finding a new email service.

Moxximummy about Gmail - Email by Google