OzarkEdge
Part of the Furniture
Given many variables and unknowns, this is my attempt to prescribe a baseline configuration of Channel Bandwidth and Control Channel (dual-band WiFi6 US)... humor me! 
Channel Bandwidth
20-40-80-160 (auto) - router varies its max bandwidth to suit its radio space.
fixed - user fixes router max bandwidth, subject to DFS.
Client should connect at its best bandwidth, subject to router max bandwidth and client channel support.
Control Channel
Auto - router varies its control channel to suit its radio space, subject to user exclusion of DFS control channels.
fixed - user fixes router control channel, subject to DFS.
Client must support control channel.
Baseline Configuration
2.4 fixed - 20MHz bw (courtesy); ch 1,6,11
2.4 auto - 20MHz bw; ch Auto (1-11)
5.0 fixed, low DFS - 160MHz bw; ch 36-48 (non-DFS)
5.0 auto, low DFS - 20-40-80-160MHz bw; ch Auto, excluding DFS channels (36-48,149-165)
160MHz bw uses DFS ch 52-64.
5.0 fixed, high DFS - 20-40-80-160MHz bw; ch 100-116
Uses DFS ch 100-128 (aka 5-2 band/dedicated backhaul).
5.0 fixed, no DFS - 80MHz bw, disable 160MHz; ch 36-48,149-161
5.0 auto, no DFS - 20-40-80MHz bw, disable 160MHz; ch Auto, excluding DFS channels (36-48,149-161)
Start with 2.4 fixed/5.0 fixed, low DFS; evaluate backhaul/client connection performance for various control channels; if WiFi/other interference persists, switch to auto; if radar/DFS interference persists, switch to no DFS.
OE

Channel Bandwidth
20-40-80-160 (auto) - router varies its max bandwidth to suit its radio space.
fixed - user fixes router max bandwidth, subject to DFS.
Client should connect at its best bandwidth, subject to router max bandwidth and client channel support.
Control Channel
Auto - router varies its control channel to suit its radio space, subject to user exclusion of DFS control channels.
fixed - user fixes router control channel, subject to DFS.
Client must support control channel.
Baseline Configuration
2.4 fixed - 20MHz bw (courtesy); ch 1,6,11
2.4 auto - 20MHz bw; ch Auto (1-11)
5.0 fixed, low DFS - 160MHz bw; ch 36-48 (non-DFS)
5.0 auto, low DFS - 20-40-80-160MHz bw; ch Auto, excluding DFS channels (36-48,149-165)
160MHz bw uses DFS ch 52-64.
5.0 fixed, high DFS - 20-40-80-160MHz bw; ch 100-116
Uses DFS ch 100-128 (aka 5-2 band/dedicated backhaul).
5.0 fixed, no DFS - 80MHz bw, disable 160MHz; ch 36-48,149-161
5.0 auto, no DFS - 20-40-80MHz bw, disable 160MHz; ch Auto, excluding DFS channels (36-48,149-161)
Start with 2.4 fixed/5.0 fixed, low DFS; evaluate backhaul/client connection performance for various control channels; if WiFi/other interference persists, switch to auto; if radar/DFS interference persists, switch to no DFS.
OE
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