Things to check are
Settings>notifications >advanced settings. Toggle on manage notification catagories for each app.
Settings>notifications >app notifications. Tap on all apps you are interested in. Tap notification catagories. Toggle on all that apply.
Settings> sounds and vibration> volume. Ensure notifications volume slider is turned up to audible level.
Settings> sounds and vibration>separate app sound. Ensure this is toggled off.
It is also advisable to wipe cache partition after any update
Plug into a working PC or laptop
https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/