@NEOTCO The thread you mentioned concerns a RE with Firmware Version: 1.0.12 Build 221109 Rel.31477n (6985) Your RE is with Firmware Version: 1.0.13 Build 231115 My guess is that if it was a bug they...

@NEOTCO According to the thread you've posted its's obvious that the extended wireless network can't be disabled.

@wepeetech Update your AC1200 v1 to the latest FW from here. Switch to AP mode an configure using this guide (Case 1). Use the guide you posted for configuring the print server.

@Raadghast If you use an ONT device you can just switch VR280 operation mode to wireless router mode and use its LAN4/WAN port to connect the ONT.

@Based_On_Cringe Go through this thread for more details. It's about general wireless connection, not a particular router or wireless device.

@N3M3S1S There's no setting for this feature - it's enabled by default