only can connect to 5ghz?

i bought fenvi bcm94360cd card which works perfectly on windows and worked out of box in macos but wifi had some problems in macos i can't connect to 2.4ghz sometimes it connects but it's very slow and unstable but if i connect to 5ghz it works just fine this does not happens in windows i tried bcrmfixup and resitting the antenas which didnt help please help!