Sundance I had the same problem. That is a music computer that I want off-line and an internet computer. What I have done is purchase a KVM switch, that is a Keyboard, Video, Mouse switch:
https://kceve.com/product/2x1-usb-3-0-kvm-switch/

This allows one keyboard and one mouse control two computers. I picked the above KVM switch as it also allows me to content a printer and a USB flash memory stick also, i.e. that eliminates the plugging and unplugging of the memory stick.

I keep the Ethernet card disabled on my music computer; you do this via the device manager. When I need to update a program I activate then immediately after disable it again.

FYI - I am also looking for a Win 11 internet computer. I am leaning towards a micro computer. You can get a some for under $400. You might want to check them out also.

My momma didn't raise a fool. And if she did it, was one of my brothers.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware