Missing "iPhone USB" port in internet sharing

I recently discovered the iPhone USB ports in internet sharing are gone (s2).

s1

s2

s3

It used to be available for selection no matter if the iPhone is connected to the computer (s1). Now it can only be seen from here when the personal hotspot on iPhone is active. The same port, iPhone USB, has the same pattern in network preference.

By selecting the USB ports as internet sharing output, the internet connection from the MacBook can be tethered to iPhone. While the internet sharing can still be enabled when using iPhone personal hotspot (s2), the iPhone won't be using any internet connection of the computer. Turning off the cellular data on iPhone will disable the hotspot thus remove the iPhone USB port on the computer subsequently without disabling the internet sharing (even with all ports unchecked [s3]). In this situation, the iPhone will neither use the connected wifi (no wifi icon in status bar but checked mark next to the connected wifi name in network settings) nor use the internet from the computer. Upon disconnection from the cable, the iPhone will suddenly regain internet connection via wifi.

I'm using macOS 10.15.4 and I was pretty sure it has worked on Catalina before. Does anyone know solutions other than try resetting the entire network config? Many thanks.