My ps5 won’t pick up my Iphone’s hotspot

Contact your operator. In some countries (I don't know about the US, though), operators have supplied users a patch for the iPhone that allows hotspot to work both for IPv4 and IPv6. Users have been able to connect their PS5 afterwards.

Source: Partage de connexion pour la playstation… - Communauté Apple.

Personal Hotspot does not connect via an ipv6 address. It uses a standard IPV4 address in the range 192.0.0.x. However, it is 5GHz only, and doesn’t support the 2.4GHz Wi-Fi band. And there is nothing you can do to change that, as pretty much all devices made in the past 10 years support 5GHz.

Sorry, I meant your carrier for your cellular plan.