Asus RT18U does not switch to 40 mhz and N mode?

Question

network hardware

Maybe I don't understand something. I went into the router settings , set the channel width to 40mhz and rebooted the N mode , downloaded the Wi Fi analyzer program, 20mhz is indicated in it , I go further, now I download the inssider program

spoiler

writes supposedly the value 802.11b is used , I've been racking my brain for a week now, I can't figure it out, who will tell the guys

Answer 1

It depends not only on the access point, but also on the client equipment

Answer 2

I have seen locked wifi adapters under 20 mhz, most likely the router is locked under the Russian Federation
, they themselves support but are locked