I have Ethernet backhaul on as well and see the hidden ssids also. But I have mine set to 80mhz and my devices are connecting at 80mhz.
How do you check it? I use Netspot app, and asuswrt wireless log. Netspot says my SSID is 40 mhz bandwidth, the thing is ASUS System log- Wireless shows in 5ghz band(I have deleted mac's):
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SSID: "ASUS"
noise: -91 dBm Channel: 36/80
BSSID: xx:xx:xx:xx:xx:xx Capability: ESS RRM
Supported Rates: [ 6(b) 9 12(b) 18 24(b) 36 48 54 ]
HE Capable:
Chanspec: 5GHz channel 42 80MHz (0xe02a)
Primary channel: 36
HT Capabilities: 40Mhz SGI20 SGI40
Supported HT MCS : 0-15
Supported VHT MCS:
NSS1 Tx: 0-11 Rx: 0-11
NSS2 Tx: 0-11 Rx: 0-11
Supported HE MCS:
80 Mhz:
NSS1 Tx: 0-11 Rx: 0-11
NSS2 Tx: 0-11 Rx: 0-11
Interference Level: Acceptable
Mode : AP Only
DFS status: state IDLE time elapsed 0ms radar channel cleared by DFS none
Channel Information
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Channel 36 A Band
Channel 40 A Band
Channel 44 A Band
Channel 48 A Band
Channel 52 A Band, RADAR Sensitive
Channel 56 A Band, RADAR Sensitive, Passive
Channel 60 A Band, RADAR Sensitive, Passive
Channel 64 A Band, RADAR Sensitive
Channel 100 A Band, RADAR Sensitive
Channel 104 A Band, RADAR Sensitive, Passive
Channel 108 A Band, RADAR Sensitive, Passive
Channel 112 A Band, RADAR Sensitive
Channel 116 A Band, RADAR Sensitive, Passive
Channel 132 A Band, RADAR Sensitive, Passive
Channel 136 A Band, RADAR Sensitive, Passive
Channel 140 A Band, RADAR Sensitive, Passive
Stations List
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idx MAC Associated Authorized RSSI PHY PSM SGI STBC MUBF NSS BW Tx rate Rx rate Connect Time
xx:xx:xx:xx:xx:xx Yes Yes -51dBm ac Yes Yes No No 2 80M 780M 6M 00:04:07
xx:xx:xx:xx:xx:xx Yes Yes -51dBm ax No Yes Yes No 2 80M 1201.0M 1201.0M 00:04:38
xx:xx:xx:xx:xx:xx Yes Yes -53dBm ax Yes Yes No No 2 80M 1020.8M 6M 01:05:46
xx:xx:xx:xx:xx:xx Yes Yes -50dBm ac Yes Yes Yes No 2 80M 866.7M 433.3M 10:06:55
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BW 80 means that devices are connecting at 80 mhz?