Setting up wpa_supplicant as 5GHz accesspoint fails on all channels - wifi

Question

I am attempting to run wpa_supplicant as a 5GHz access point on a NUC installed with ubuntu 20.04 LTS. - But every single channel I try to use, it always fails with wlp2s0: Failed to start AP functionality.
My wpa_supplicant.conf:
network={
ssid="TESTAP5g"
mode=2
key_mgmt=WPA-PSK
psk="secretpass"
frequency=5825
}
When i try to check the available channels with iw reg get:
global
country DK: DFS-ETSI
(2400 - 2483 # 40), (N/A, 20), (N/A)
(5150 - 5250 # 80), (N/A, 23), (N/A), NO-OUTDOOR, AUTO-BW
(5250 - 5350 # 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS, AUTO-BW
(5470 - 5725 # 160), (N/A, 26), (0 ms), DFS
(5725 - 5875 # 80), (N/A, 13), (N/A)
(57000 - 66000 # 2160), (N/A, 40), (N/A)
And the frequencies shown by iw list:
Frequencies:
* 5180 MHz [36] (22.0 dBm) (no IR)
* 5200 MHz [40] (22.0 dBm) (no IR)
* 5220 MHz [44] (22.0 dBm) (no IR)
* 5240 MHz [48] (22.0 dBm) (no IR)
* 5260 MHz [52] (22.0 dBm) (no IR, radar detection)
* 5280 MHz [56] (22.0 dBm) (no IR, radar detection)
* 5300 MHz [60] (22.0 dBm) (no IR, radar detection)
* 5320 MHz [64] (22.0 dBm) (no IR, radar detection)
* 5500 MHz [100] (22.0 dBm) (no IR, radar detection)
* 5520 MHz [104] (22.0 dBm) (no IR, radar detection)
* 5540 MHz [108] (22.0 dBm) (no IR, radar detection)
* 5560 MHz [112] (22.0 dBm) (no IR, radar detection)
* 5580 MHz [116] (22.0 dBm) (no IR, radar detection)
* 5600 MHz [120] (22.0 dBm) (no IR, radar detection)
* 5620 MHz [124] (22.0 dBm) (no IR, radar detection)
* 5640 MHz [128] (22.0 dBm) (no IR, radar detection)
* 5660 MHz [132] (22.0 dBm) (no IR, radar detection)
* 5680 MHz [136] (22.0 dBm) (no IR, radar detection)
* 5700 MHz [140] (22.0 dBm) (no IR, radar detection)
* 5720 MHz [144] (22.0 dBm) (no IR, radar detection)
* 5745 MHz [149] (22.0 dBm) (no IR)
* 5765 MHz [153] (22.0 dBm) (no IR)
* 5785 MHz [157] (22.0 dBm) (no IR)
* 5805 MHz [161] (22.0 dBm) (no IR)
* 5825 MHz [165] (22.0 dBm) (no IR)
This is cutout from wpa_supplicant -dd log:
nl80211: Set freq 5825 (ht_enabled=0, vht_enabled=0, he_enabled=0, bandwidth=0 MHz, cf1=0 MHz, cf2=0 MHz)
* freq=5825
* he_enabled=0
* vht_enabled=0
* ht_enabled=0
* channel_type=0
nl80211: Failed to set channel (freq=5825): -22 (Invalid argument)
nl80211: Set mode ifindex 3 iftype 2 (STATION)
nl80211: Failed to set interface 3 to mode 2: -16 (Device or resource busy)
nl80211: Try mode change after setting interface down
nl80211: Set mode ifindex 3 iftype 2 (STATION)
nl80211: Mode change succeeded while interface is down
"Resource busy?" I know for a fact there is no wpa_supplicant running before starting it up and the wifi interface is available and can scan just fine (also able to see other access-points using 5GHz channels, that I cannot use either).
On my laptop I had similar problem. iw list frequencies also showed all channels with [no IR], but I was still able to run access point on channel 165 without problem.
If i put in freq_list= or channel=0 in the wpa_supplicant.conf, it just falls back to being an access point on channel 11 every time (which is 2.4GHz), even though only 5GHz frequencies are listed. - And BTW access point on 2.4GHz works just fine.
Do any of you have any pointers to what I'm doing wrong or how i can investigate further? Could it a hardware limitation? If more info is needed, let me know and I will update.