Cannot join wifi

I had to power cycle HA a couple of times (network was very unstable, this causes HA to go nuts and start flooding the network with mDNS queries unfortunately) and since then I cannot join wifi anymore.

Wifi was already very unstable before, HA would loose wifi and stop attempting to reconnect a couple of times a week.

I am running the latest HA on a raspberry Pi 4.

When I run ha network update wlan0 --ipv4-method auto --ipv6-method auto --wifi-auth wpa-psk --wifi-mode infrastructure --wifi-ssid REDACTED --wifi-psk REDACTED --log-level debug

the output is “400 Bad Request”:

DEBU[0000] Adding homedir to searchpath                  homedir=/root
INFO[0000] No configfile found                          
DEBU[0000] Debug flags                                   apiToken=8dad0fb058a27f8fe741dca1ee1cbd3e11d406678be67cc4055ab0a05ec3ae39e5713537db45e7d45982c7ca19f594b569224511eef43ecd cfgFile= endpoint=supervisor logLevel=debug noProgress=false rawJSON=false
DEBU[0000] network update                                args="[wlan0]"
DEBU[0000] [GenerateURI]                                 base=supervisor command="interface/{interface}/update" section=network
DEBU[0000] [GenerateURI] Result                          uri="http://supervisor/network/interface/{interface}/update" url="http://supervisor/network/interface/%7Binterface%7D/update" url(string)="http://supervisor/network/interface/{interface}/update"
DEBU[0000] Request body                                  options="map[enabled:true ipv4:map[method:auto] ipv6:map[method:auto] wifi:map[auth:wpa-psk mode:infrastructure psk:REDACTED ssid:REDACTED]]"
DEBU[0024] Response                                      body="{\"result\":\"error\",\"message\":\"Activating connection failed, check connection settings.\"}" fields.time=24.969341951s headers="map[Content-Length:[87] Content-Type:[application/json; charset=utf-8] Date:[Tue, 01 Jul 2025 19:35:03 GMT] Server:[Python/3.13 aiohttp/3.12.13]]" received-at="2025-07-01 21:35:03.370574908 +0200 CEST m=+24.977804660" request="&{POST http://supervisor/network/interface/wlan0/update HTTP/1.1 1 1 map[Accept:[application/json] Authorization:[Bearer 8dad0fb058a27f8fe741dca1ee1cbd3e11d406688be67cc4055ab0a05ec3ae39e5713537db45e7d45982c7ca19f594b569224511eef43ecd] Content-Type:[application/json] User-Agent:[go-resty/2.16.5 (https://github.com/go-resty/resty)]] {} 0x2292e0 164 [] false supervisor map[] map[] <nil> map[]   <nil> <nil> <nil>  {{}} <nil> [] map[]}" status="400 Bad Request" statuscode=400
Error: Activating connection failed, check connection settings.

if anyone has an idea.

I want to connect wifi to guest vlan and LAN to the normal home vlan.

HA is not meant to run as a router in a multihomed setup and your Guest network might be using client segregation, so all you can do on the guest network is access the internet.

Why not use the UI ?

It fails in the UI as well, I forgot to mention. I only used the CLI because the UI was failing and I wanted more logs.