Roland FA06 pitch bend issue

Hello all,
Lately I’ve been noticing after playing for few mins, the pitch bend goes off while going pitch down only. I’m mostly using it on the lower keys as bass and pitch down, and using +/-12, in just 15mins, it starts to go 11 down, going up is totally fine and keeps changing and goes less and less on pitch down…
That day I ended up setting the pitch to +/- 24, to be able to get it at 12 down.
I have thought maybe it’s from the pitch bend gear when I found syntaur page to order parts, and they didn’t have it.
I continued checking the keyboard, I thought of using the D-Beam for pitch bend to see if it goes as what I set it up, but it acts the same as the pitch bend gear…
so it look like it’s something firmware related…

on the other hand, i still need pitch bend gear as a spare, from where i can get it?

Any luck with this? I am having exactly the same problem. I’ll update the latest firmware and see what happens.