Hi there, altc173.
Restarting your iPhone 13 was a good first step to take. Do you notice the issue to continue if you connect your iPhone 13 to another internet network (mobile/cellular data or another Wi-Fi network)?This can help show if the no video and audio issue is from the internet network having issues or if the issue is something else.
Connect to a Wi-Fi network
1.) From your Home screen, go to Settings > Wi-Fi.
2.) Turn on Wi-Fi. Your device will automatically search for available Wi-Fi networks.
3.) Tap the name of the Wi-Fi network that you want to join. Before you can join the network, you might be asked to enter the network's password or agree to terms and conditions.
Connect to Wi-Fi on your iPhone, iPad, or iPod touch - Apple Support
You'll also want to ensure that all installed apps are fully up-to-date, which may also help since the latest app version will be installed:
How to manually update apps on your iPhone or iPad
1.) Open the App Store.
2.) Tap your profile icon at the top of the screen.
3.) Scroll to see pending updates and release notes. Tap Update next to an app to update only that app, or tap Update All.
How to manually update apps on your Apple device - Apple Support
Take care!