@Shariff As per the product specification, C6U doesn't support the printer server, you can check it below: https://www.tp-link.com/home-networking/wifi-router/archer-c6u/#specifications

@Lav90 Below is a setup video for your reference to install your wireless router: https://www.tp-link.com/support/setup-video/ But if you still failed, please refer to the troubleshooting suggestions...

@sam.booz Go through this thread to see what you can do in your case - [Troubleshooting] Router Disconnects from Internet.

@Saddle Where did you change the device names on the Tether app? Can we have some screenshots? You can mask/cover the MAC address for it. What if you do that via the router web GUI? Will it be saved...

@7ixj If you cannot register the TP-Link cloud account successfully, please check the following troubleshooting guide to locate which case are you with: https://www.tp-link.com/support/faq/2586/

@Tufkat Are both the 2.4G and 5G wireless connections having the same issue? How many of them? Try a different wireless channel, change channel width to 40MHz for the 5G and 20MHz for the 2.4G,...