After downloading 16.3.1 on both my iPhone 14 and my iPad neither will connect to wifi. However my husband’s iPhone 14 will. Nothing has changed except new os

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

If none of the steps in that article resolve the problem, let’s do some troubleshooting:

• Is the problem with all networks or one specific network?
• Go to Settings/Wi-Fi; do you see the network?
• If you do, tap on it and see what it says; does it prompt for a password, does it connect?
• If it gives an error, what is the error?
• If it connects, tap on the i next to the network name and note the IP address; it should start with either 10.0 or 192.168. If it begins 169.254 that is a router problem; the router is not assigning IP addresses. Check out the router manufacturer’s troubleshooting help.

Try to do a force restart -> Force restart iPhone – Apple Support (UK)

Restart your router.

And, if you use VPN delete the VPN app and profile.