I installed Manjaro Linux onto my Macbook Air 2013, which has a bcm4360 wifi network controller. I've two routers, one from the ISP, and a Linksys EA8500 with latest dd-wrt. I can connect to the ISP's router, on channel 36, so 5 Ghz connection is working with the broadcom wl driver, but I'm unable to create an 5 Ghz connection with the Linksys router, only 2.4 Ghz is working. At first, I used the router with auto channel settings (the 5 Ghz connection appears on the scanning list, but during connect, NetworkManager reports that connection took too long and drops it), but I've googled the problem, and found that lower channels are preferred by the broadcom wl driver. but changing to channel 40 didn't fix the problem. From the same machine, MacOS, Windows 10 connects perfectly to the 5 Ghz channel in auto channel setting and manual channel setting too. I've tried manually connecting with netctl, but the result is the same. I tried the wifi channels from 36 to 64, I've tried without security, but it won't connect. The ISP router uses the same encryption type as the Linksys router (WPA2 PSK AES). I'm out of ideas, I use the latest stable version with 4.19 kernel, KDE, NetworkManager. Any help appreciated.