Scirocco Central

Hello,
i've been dealing with this issue for days..
Scirocco 1.4 TSI CAXA, 2010

So, the left rear turn signal is not flashing.
Bulb checked, it’s fine.
Relays/fuses are fine (checked by my mechanic)
The sockets are fine and the voltage is there.

I tried switching the left light with rear and it’s working, so it's not the board either .

But when I put them back, the left turn signal is just not working. Fronts are. The arrow is not going faster, as it is when the bulb is broken.

Do you guys have any ideas, before I leave the car in shop for new wirings..?

Much appreciated, thanks in advance!

That’s a really strange one, the car isn’t sensing there’s a problem with it, are all of the other lights in the same cluster working as they should? You say you have tested the left light on the right hand side, have you tested the right in the left? The only thing I could possibly see as being wrong is there may be damage or corrosion to the connector, you have said there is voltage to the light but if that was the case the light should work, I think I would be looking more closely at the connector and the wiring to it.
Hope this helps

Sounds like a ground problem.