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We should never share our main network password as a QR code, rather enable your guest network in your router and share it. In this way, you don’t have to reconnect to the guest network from your phone, anytime your guest wants to connect to your router, just show them the printer QR code. Never share your main network with a guest network, even if they have access to your network devices, they cannot access any of your devices from outside also. Only share guest network with your phone settings.