pb with bluetooth passthrough on linux (arch) with WML-C43 wii dongle

[bachfugue]

Hello,
I embarked on using a real wii bt module following: https://forums.dolphin-emu.org/Thread-how-to-wire-a-wii-s-bluetooth-module-to-a-pc-usb-port
After a bit of soldering, it works fine on windows (with the zadig driver): remembers pairing with A button press for example. So I guess, I got the soldering right.

On Arch Linux, I added, in /etc/udev/31-usb-device.rules, the line
SUBSYSTEM=="usb", ATTRS{idVendor}=="057e", ATTRS{idProduct}=="0305", TAG+="uaccess"

So if I enable passthrough, the module is detected and I can pair by resetting all saevd pairings, then pair again.
The problem is: when I close a game and re-open one, if I press on A button, the leds blink 1 or 2 seconds then stop. This probably means the pairing is rejected by the software.

Point is: I tried with another bluetooth adapter
SUBSYSTEM=="usb", ATTRS{idVendor}=="0a12", ATTRS{idProduct}=="0001", TAG+="uaccess"
And, after initial pairing, it remembers my wiimotes: I can reconnect by pressing A.
It works as expected (only thing being: not enough bandwidth fro intense 4 wiimotes).

So, I'm wondering if I did anything wrong: the wii bt module is usable but I have to re-pair each time I launch a game (which is annoying and sometimes demands several tries).

Thanks

[JMC47]

It depends on your adapter whether it will successfully save the pairings. Dolphin does have a backup to this, but it doesn't seem to be very compatible on BlueTooth devices that forget the pairings.

[bachfugue]

Yes, but my problematic bt adapter is a real wii bt module which is supposed to remember pairing (and it does this very well but only under windows).
What is strange: when I press the A button, the leds blink for a very short time: it seems to indicate that the pairing is rejected after 1 or 2s.

[bachfugue]

I tried with 2 other bluetooth adapters on linux: they all accept passthrough and they remember pairing.
The real wii bluetooth module is the only that seems to immediately reject the re-pairing (leds blink only 1 second).
Wondering if there's any way to display the messages during the bluetooth transaction with dolphin.
Strange, really, as: my real wii module seems to work fine in Windows and I tested it outside of Dolphin on Linux: it works fine.
I tried repairing the Nand: no improvement.
If you have any idea, they're welcome.