Mc Cthulhu doesn't work on real PS1/PS2

Hey guys,
My arcade stick with the cthulhu board works perfectly with pretty much anything (PC, PS3, GC, Saturn, PC Engine), and also work with various adaptors that use the PSX connection.
But strangely, it just doesn’t work on both PS1 and PS2.
I checked the continuity of the cable from the psx plug and the RJ-45 down to the board pins, and they are all good.
I also updated the firmware to 2.3, tested with 1ms and 10ms versions.
I tried a different cable, different ports.
Nothing fixes it.
Does any of you guys know how to make it work?
Is it because the mccthulhu boots in analog mode right away? Is there a way to prevent that?
Thanks.

By default the cthulu activates both dpad and left analog stick at the same time.

You can hold start when plugging in the stick to enable only one. And hold select when plugging in to enable only the other.

I dont remember which is which.

You’re right, holding select enable the joystick only, and the start enable the dpad only!
Good to know.
Sadly it only works when plugged in usb, the ps2 connection stays in Analog mode all the time.

Even weirder, in ps2 mode when I push both start and select (after plugging it in), the R1-L1-R2-L2 are disabled, and the stick is activating those buttons, along with the analog axises. It doesn’t really help on anything, and it can’t be disabled unless I unplug it.

Edit: I just realized with my ps2->usb adapter, the digital mode always shows the analog stick instead of the dpad. My bad, it is in digital mode then. So the problem comes from something else obviously.
Can there be a problem with the ps1/ps2 mode detection with real hardware?

Edit2: I saw few other people having the same issue, but no solution so far.