Wireless network with bfwm sometimes works and sometimes doesn't

Hi all,

I'm not sure how to debug this systematically. I have OpenBSD 7.5 on
Raspberry Pi 4 (but I had the same problem with 7.4 as well).
Sometimes the computer connects to the wireless network at boot, and
sometimes it doesn't, without any obvious pattern. Whenever it
connects, it works fine and doesn't seem to be flaky or unusually
slow, though I didn't measure. If it doesn't connect, despairingly
calling `doas sh /etc/netstart bwfm0` or `doas ifconfig bwfm0 inet
autoconf` sometimes helps, but more often doesn't. Other computers
connected to the same network don't seem to be affected.

This is what the output of ping looks like when it doesn't connect:

PING 192.168.0.1 (192.168.0.1): 56 data bytes
ping: sendmsg: Can't assign requested address
(these two lines repeat until I ^C)
--- 192.168.0.1 ping statistics ---
9 packets transmitted, 0 packets received, 100.0% packet loss

This is what the output of `ifconfig bwfm0` looks like when it doesn't
connect:

bwfm0:
flags=a48843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,AUTOCONF6TEMP,AUTOCONF6,AUTOCONF4>
mtu 1500
lladdr e4:5f:01:4d:c2:2c
index 4 priority 4 llprio 3
groups: wlan
media: IEEE802.11 autoselect (OFDM6 mode 11a)
status: no network
ieee80211: join NETWORK_IN_QUESTION_5G chan 112 bssid
f0:af:85:9a:e4:23 -69dBm wpakey wpaprotos wpa2 wpaakms psk wpaciphers
ccmp wpagroupcipher ccmp
inet6 fe80::e65f:1ff:fe4d:c22c%bwfm0 prefixlen 64 scopeid 0x4

This is my /etc/hostname.bwfm0:

join NETWORK_IN_QUESTION_5G wpakey PASSWORD
inet6 autoconf
inet autoconf

I would appreciate any suggestions.

Regards
Stanislav Syekirin