DFS-CAC freq not as requested in config

[undef]

Hi, I observed this behaviour on a xiami mini running 19.07.3.
it seems hostapd is not scanning the correct channel.

note the channel 56 in config and freq=5260 chan=52 in the logs.
the wifi will come up on channel 52 instead of 56.

why is channel 56 not being scanned?
thanks!

/etc/config/wireless:

config wifi-device 'radio0'
        option type 'mac80211'
        option hwmode '11a'
        option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
        option htmode 'VHT80'
        option disabled '0'
        option channel '56'
        option legacy_rates '0'
        option country 'BE'

while the logs show:

Mon Nov  2 17:27:32 2020 daemon.notice hostapd: wlan0: interface state UNINITIALIZED->COUNTRY_UPDATE
Mon Nov  2 17:27:32 2020 daemon.notice hostapd: wlan0: interface state COUNTRY_UPDATE->HT_SCAN
Mon Nov  2 17:27:33 2020 daemon.notice hostapd: Switch own primary and secondary channel to get secondary channel with no Beacons from other BSSes
Mon Nov  2 17:27:33 2020 daemon.notice hostapd: wlan0: interface state HT_SCAN->DFS
Mon Nov  2 17:27:33 2020 daemon.notice hostapd: wlan0: DFS-CAC-START freq=5260 chan=52 sec_chan=1, width=1, seg0=58, seg1=0, cac_time=60s
Mon Nov  2 17:27:34 2020 daemon.notice hostapd: handle_probe_req: send failed
...
Mon Nov  2 17:28:33 2020 daemon.notice hostapd: handle_probe_req: send failed
Mon Nov  2 17:28:34 2020 daemon.notice hostapd: wlan0: DFS-CAC-COMPLETED success=1 freq=5260 ht_enabled=0 chan_offset=0 chan_width=3 cf1=5290 cf2=0

[mk24]

Channels 52 and 56 are both in the same 80 MHz allocated group of channels. The on-air result is the same whether you choose 52, 56, 60, or 64 with mode VHT80. Some drivers also refer to this frequency / mode selection as channel 58.
This chart is all over the Internet.