not getting tab notifications on website I use frequently on Safari

I use a website called Fetlife.com and that site uses browser tab notifications to tell me if someone has posted on the feed or messaged me if I am on another tab or another website.

My problem is Safari doesn’t give me these notifications all day. So I miss posts and don’t find out someone messaged me until an hour later.

I wish there is a way to fix this in a future update cause I love Safari but this is really annoying.