iPhone 14 Pro Wi-Fi Slow
iPhone 14 Pro Wi-Fi very Slow
iPhone 14 Pro Max, iOS 18
How slow? Did you measure the speed with a website like fast.com, speedtest.net or the speedtest app? Have you compared this with the speed seen on other devices on your network?
Do you use VPN? If so, delete the VPN profile in Settings/General/VPN & Device Management/VPN. Don't just turn it off; delete the profile.