I am using RB4011iGS+5HacQ2HnD and capsman. I have 2 different SSIDs for 2.4 GHz and 5 GHz networks. All used to work fine. Unfortunately, after update to ROS 6.47 (I used 6.47rc2 lastly) I started to have problems with 5 GHz connection on my laptop. Unfortunately coming back to 6.47rc2 didn't change anything. I realized, that the problem is in band width. In capsman the connection is set to XXXXXXXX so the device choses best (I guess). Unfortunately, when it is eeeeCeee my laptop doesn't connect at all while iPhone 11 Pro connects with no problems. When I swicth to Ceeeeeee my lapotop connects and iPhone says "worng password" while in the RB log I receive "disconnected unicast key exchange timeout". How can I configure my 5 GHz wifi to work properly on all devices? When I turn off DFS, the channel is no longer that wide and speed is aprrox. 150 Mbps while with DFS turnd on it reaches 300 Mbps (however it is still 50% of my internet connection but this is all I can get).
How to solve this?

Nobody?

You only have the RB4011 for wifi? The first think I would do is get rid of capsman, it only complicates the setup and IMHO is not required for
a. anything less than 3 separate APs
b. dangerous for a new user just learning RoS

Then post your config for review
/export hide-sensitive file=anynameyouwish

XXXXXXXX and Ceeeeeee are very wide (160 MHz bandwidth). You will need at least some DFS channels to find a block of channels that is 160MHz wide. And those DFS channels might include 120-124 or 128, so your AP will then be silent for 10 minutes after every change to the 5 GHz. Not all end-user devices are capable of using all channels.
Do you really need the 160MHz bandwidth? I would rather go for 80MHz, or even 40 MHz. (Ceee or Ce) with dual spatial stream (866MHz and 400 MHz interface rate, 50%-60 data rate)

Forgive the noob question, but does the 160GHz DFS selection preclude slower clients from connecting at 80GH, or 40GHz. If it doesn't, wouldn't 160GHz be a better (more encompassing) choice, even if all devices are brought down to the smallest bandwidth?

Also, for a router that's in a set-it-up and forget-it, 10 mins doesn't seem like much, unless you're suggesting the center channel is changing all the time, no?