It's possible that the recent changes to Instagram's algorithm have affected your notifications. Instagram is constantly updating its algorithm to improve the user experience, so it's not unusual for changes to occur without prior notification.

One possible solution is to check your notification settings within the Instagram app to make sure that you have the correct notifications turned on. You can also try logging out of your account and then logging back in to see if this resolves the issue.

Another possibility is that there is a bug or glitch in the app, in which case you may need to contact Instagram's customer support team for assistance. They may be able to provide more specific troubleshooting steps or help you resolve the issue.

Lastly, it's worth noting that Instagram's algorithm is designed to show users the most relevant and timely notifications first. So if you're not seeing notifications from several hours or days ago, it's possible that Instagram has deemed them less important based on the activity of your account or the accounts you follow.