Apps not updating on Wi-Fi networks on my iPhone

Please reset your network settings.

Reset your network settings

>>If you're using iOS or iPadOS 15 or later, tap Settings > General > Transfer or Reset [Device] > Reset > Reset Network Settings.

If you're using iOS or iPadOS 14 or earlier, tap Settings > General > Reset > Reset Network Settings.

This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.<<

If your iPhone or iPad won't connect to a Wi-Fi network - Apple Support

Reset everything

What happens on cellular connection? How fast and stable/reliable is your WiFi?

Why aren’t you updating on cellular if you have full bars? What error messages are you receiving when updates fail? Are you using a VPN or have a VPN profile installed?