Go to Device Care > Battery - Open Background usage limits, then disable Put unused apps to sleep - Go back and open More battery settings, disable Adaptive battery.
Go to Settings > Apps, find Facebook and Instagram, tap Battery and select Unrestricted or Optimized, depends on your choice.
Did other's troubleshooting suggestions work? If it did, you can click the "Accept as Solution" on the comment that helped fixed your issue.
If the problem still persists, then try removing your sim card and check if the notifications coming in are still delayed. It might be that the sim card you're using has compatibility issues with your smartphone device. You can check out this post for more information about the issue and how they resolved the issue: https://r1.community.samsung.com/t5/galaxy-s/galaxy-s22-delayed-notifications-solved/td-p/15981059?m...
