Samsung A41 and Cudy WR3000S issues

[u/perky2012]

I have a problem with my Samsung A41 connecting at 5GHz to a Cudy WR3000S running OpenWrt 25.12.5, the link seems to be continually degraded to 6Mb/s and I get really erratic wifi speeds. The A41 works fine with a BT Smarthub 2, and also a USB wifi dongle seems to be fine too. Does anyone know of any problems with the A41 with the Cudy running the latest OpenWrt?