Gideon, have you tried Windows 7? Windows 8 and 8.1 are not supported by MA260. On their website, System Requirements are Windows 7/Vista/XP (32/64bits)....

Not sure. Did you contact printer's technical support to ask help? Maybe you need to change some other settings on router page?

TD-W8968 is the main router and normally repeater should use the same SSID and password. If it cannot, you should check the linksys device and its firmware.

Is it possible for you to install the WN823N on a different PC to test if the problem continues? Have you tried to update the driver? https://wikidevi.com/wiki/TP-LINK_TL-WN823N_v1

http://www.diffen.com/difference/USB_2.0_vs_USB_3.0

The firmware version is so old... Why not upgrade the latest firmware? http://www.tp-link.com/en/download/TL-WR841N_V9.html#Firmware Upgrade the latest firmware, reset and reconfigure it to test if...