What a client connects to is based solely on it's proprietary client  wireless chipset/driver algorithms.  Apple lists theirs plainly enough . They don't really list anything for channel width in 6GHz but they do mention  it  for 5 GHz... https://support.apple.com/en-us/102169#:~:text=When%20auto%2Djoining%20networks%2C%20macOS,private%20networks%2C%20then%20public%20networks.&text=Known%20networks%20are%20scored%20based,a%20network%2C%20its%20score%20decreases.   ... View more