HI folks, I just wanted to let you know that I found the solution to the issue with DHCP that has been reported on several posts in this forum.

The problem is not related to DHCP server or client. The root cause is related to the new WIFI privacy features available on iOS and Android to avoid device traking in the network.

If you just turn off the private address for your network it will work.

Turn a private address off for a network

https://support.apple.com/guide/iphone/use-a-private-network-address-iph6b324bb33/ios  

Turn iCloud Private Relay on or off for a Wi-Fi network

You should also check this: https://support.apple.com/guide/iphone/protect-web-browsing-icloud-private-relay-iph499d287c2/ios

Merry Christmas!! :)

Mario