iPhone not giving alert sound sometimes for any or messaging notifications

I had the issue of iPhone not giving me any sound for notification for several apps including messaging. I tried almost everything, but this is what solved my problem:

Disable Attention Aware Alerts

This is another hack you can try to get notification alerts. The Attention Aware Alerts feature checks for users’ attention before dimming the screen brightness, expanding a notification while the phone is locked, or decreasing the volumes of certain notifications. Here’s what to do:

• Select the Face ID and Passcode option via the Settings.
• Enter your passcode.
• Now, scroll down to reach the Attention Aware Alerts option. Tap on it to disable it.