@Substring OK, problem settled. The PS3 controller had me wondering, and so I took a look at my recalbox.conf file. Turns out PS3 controllers were enabled, and disabling them seems to have resolved my issue.

SFC30 now reconnects just fine after a reboot and regular power cycle. Nothing to worry about !

@Substring The odd thing is my pad seems to reconnect, but the inputs have absolutely no effect.
I did a pastebin of my /var/log/messages, but it is quite long. Do you want me to paste it here, or do I look for something in particular ?

I should add that when I try to set a pad for a specific player, my sfc30 seems to show up as a PS3 controller. Very strange.

So, running an Rpi3, internal bluetooth, with an 8bitdo SFC30 (latest firmware, but I forgot the exact version).

On first try, the pad connects and pairs perfectly and almost immediately. Setting it up and using it in games works as expected.

Doesn't turn off when rebooting, and once Recalbox is up and running, it doesn't pair again.

After turning it off and on again, the pad is totally ineffective, but seems to be paired : Recalbox finds it when I try to enter the pads settings, but keeping a button pressed to enter configuration does nothing.

I had the same issue before the update. I still have to try with my BT dongle.

@Substring I had the same issue with the square bug, and those lines did the job allright. Thank you !
It might be worth adding the info in the first post.

Never mind, I just had to format the VMU by launching a game and soft resetting (A+B+X+Y+Start). Everything perfect now!

@voljega OK, so that's the normal behavior. Thanks !

Any idea about my saving issue, anyone ?

I'm having trouble with Dreamcast games. They launch allright and run smoothly, but I can't save (not enough blocks, whatever the game) and whenever I hit the hotkey, Reicast crashes and sends me back to EmulationStation. Can anyone save ?

I put the bios matching the OP md5 in the Bios folder, but it changes nothing.
I'm a bit lost.