Why does my phone drop Wi-Fi and revert to LTE when I’m at home? How do I stay connected to Wi-Fi at home?

See the following Apple articles:

Connect to Wi-Fi on your iPhone, iPad, or iPod touch

Connect to Wi-Fi on your iPhone, iPad, or iPod touch - Apple Support

If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network

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

Check the router settings -> Recommended settings for Wi-Fi routers and access points

Recommended settings for Wi-Fi routers and access points - Apple Support

If you need to sign in to your router & if you need help with your Wi‑Fi password:

If you have iOS 16:

Go to -> Settings -> tap Wi-Fi -> tap on the hideen Password -> enter Passcode -> you will then see the Wi-Fi Password

If they are On, turn Off Hotspot & VPN.