Hi Sueperbly,
Thanks for participating in the Apple Support Community. It sounds like you aren't getting notifications on your iPhone, but are getting the sound. Let's see if this helps.
If it's only happening with one or a handful of apps, follow the steps in the section "If you don't see notifications for a specific app" in Use notifications on your iPhone, iPad, and iPod touch. Let's follow all the steps there including making sure Banners are enabled among other notification settings.
If the issue continues, make sure your apps are all up-to-date using the steps in How to manually update apps on your Apple device. You mentioned updating your iOS, app developers update their apps too after an iOS update. You'll want to ensure you're running the most compatible app with the software version you're running.
Are the time and date correct? Is it set to “Set Automatically” in Settings > General > Date & Time? Incorrect Date & Time settings for Notifications can affect how Notifications are delivered.
Do you use a VPN? If so, try turning the VPN off and seeing if you get a notification. VPN's might affect your ability to receive notifications.
If the issue remains after those steps, do a quick test and ask someone you know and who has messaged you before (not a new person) to message you and see if you get a notification from that person. Also, be sure to let us know the names of any other apps this is happening with or if it's just WhatsApp.
We hope that helps with your question and take care!