For example I have this TPLink Archer C9 AC1900 which I did just that.
How? I turned on a Guest network and opted for CLIENT ISOLATION which turned off network sharing. Now that means that my main network can do sharing and the guest network does not.
I don't see your router make and model so I can't check if it can do guest networking.
Can anyone recommend a router on which file sharing can be turned off and turned on? I have a Vizio Internet ready TV wired via Ethernet to a router. File sharing being "on" on the network causes the TV to periodically freeze (a software glitch per Vizio Tech Support). I need to set up networking on the TV with file sharing turned off on the router, and then after the TV networking has been set up, I can turn file sharing back on on the router. Is there such a router that can do this? Doesn't have to be wireless. I just need a device to connect in between the current router and the TV that can turn off file sharing. Thanks.