PSA - Turn off your iPhone’s VPN before turning on your hotspot so that the connected devices will have internet access
Aside from resetting network settings, turning on maximise compatibility, this method might work for you
I had this problem for months wherein any device(iPhones, Android, Mac, Windows) that connects to my hotspot, there is no internet access for the connected device. The common problem is “DNS cannot be resolved”
For some reason, when I turned off my phone’s VPN, the connected devices had internet access suddenly
YMMV, it maybe isolated to my VPN or device only. But hopefully this can help anyone with the same problem as mine, as I haven’t found this context in the internet