Couple of data points that may be helpful.
Platform: BTT PI v1.2 D/C 2023.11.8 with the U2C CAN board
Distro: Armbian 25.8.1 Bookworm
Kernel: 6.12.43-current-sunxi64
Overlays: spidev0_0
1. Adding a sleep 5 hack did not work for me, however what does *seem* to work is inserting the following line to /etc/netplan/30-wifis-dhcp.yaml
activation-mode: manual
WiFi was still activated (which may be another bug) for at least 3 cold boots in a row (didn't have time to test more thoroughly). Here's a pastebin link from right after one such boot - https://paste.armbian.com/umijapukiy
2. The error from wpa_supplicant is
CTRL-EVENT-SCAN-FAILED ret=-1 retry=1
.Same error code (-1) is also reported when attempting a manual scan
pi@jubilee:~$ sudo iw wlan1 scan
command failed: Operation not permitted (-1)
3. Broken state of the WiFi driver seems to be correlated with mmc errors in dmesg
[ 11.490708] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 11.490745] sunxi-mmc 4021000.mmc: send stop command failed
[ 11.490856] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 11.490880] sunxi-mmc 4021000.mmc: send stop command failed
[ 11.491071] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 11.491098] sunxi-mmc 4021000.mmc: send stop command failed
[ 11.491224] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 11.491248] sunxi-mmc 4021000.mmc: send stop command failed
These are not present if wifi was activated successfully.
Here's a pastebin link from right after such boot - https://paste.armbian.com/xovixuniti
EDIT: Ran armbianmonitor -c overnight and the SD card seems fine
The results from testing /dev/mmcblk0p2 (ext4):
Data OK: 111.37 GB (233561400 sectors)
Data LOST: 0.00 Byte (0 sectors)
Average writing speed: 18.41 MB/s
Average reading speed: 22.74 MB/s
...
Health summary: OK
3. Reloading the kernel driver (8189fs) when it is already in a broken state is very slow and provokes a slew of mmc errors
$ sudo /sbin/rmmod 8189fs
pi@jubilee:~$ time sudo /sbin/modprobe 8189fs
real 2m15.835s
user 0m0.008s
sys 0m0.048s
$ dmesg
....
[ 673.262192] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.262286] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.262379] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.262471] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.262563] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.262656] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.262716] ====>_BlockWrite 101 i:0
[ 673.262742] ====>_WriteFW 230
[ 673.263001] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.263088] sunxi-mmc 4021000.mmc: data error, sending stop command
[ 673.263141] ====>_BlockWrite 101 i:0
[ 673.263162] ====>_WriteFW 230
Again the same problem is not present if WiFi was activated successfully after boot: Shutting down the interface and reloading the driver works just fine.
Please let me know if there's anything else I can collect that can help to track this down. Given this is a fresh install and has no personal data in it yet, I can share my SD card image if that would be helpful.