The router is a Brume and the antenna is a TP-Link Archer T2 Plus.
Wi-fi has been working nicely for a long time, and for some reason has stopped working.
Wireless Overview reads
Generic 802.11 Wireless Controller
Channel: ? (? GHz) | Bitrate: ? Mbit/s
and when a network is enabled, it reads
Wireless is not associated
What are the things to check now?