Fabia Speedometer 2003 ASY

Here's a Fabia where the speedometer isn't working, and it's showing this error code:

01086 - Speedometer sensor (G22).
06-10 - Signal too large - Sporadically.

I started by performing an actuator diagnosis, and it worked.
Then I checked the power supply of the G22, and it was also okay.
The signal cable to the combination unit was checked for continuity and is also okay.
Then I installed a new G22, but it still doesn't work.
I then checked the signal with the oscilloscope, and it consistently reads around 10V, even when the engine is running.
I then removed the sensor again and looked inside the transmission. There are indentations, approximately 1 cm wide, every 2-3 cm. So, it should fit.
Finally, the signal is simulated using a function generator, and the speedometer works.

Then I ran a milling head with a diameter of about 2cm, along with some recesses, over the extended sensor using a drill, but nothing changed. Perhaps the profile isn't correct.

I can't quite imagine that the new sensor is broken. The speedometer went haywire when I stalled the engine in 3rd gear without using the clutch. The owner also said it should display something after a longer drive, but sometimes it shows too much.

Quote:

Then I checked the power supply of the G22, and it was also OK. The signal cable to the combination unit was checked for continuity and is also okay. Then I installed a new G22, but it still doesn't work.

Checked for short circuits between each other?
Are the connector connections okay?

It was due to the power supply of the G22. I didn't test it under load because I don't have a Y-connector.
I pierced the positive cable, and under load, it dropped to 2 volts.