Kadjar torque converter failure

That sounds rough. Is there any weird vibration at certain speeds, or is it mostly just the slipping and grinding?

Now that you mention it, there's a judder at around 80-90 km/h, like a low-frequency vibration. Does that confirm the converter fault?

Vibration plus slipping equals torque converter trouble. The lock-up clutch is probably done. Get it to a workshop.

I feared as much. I dropped it at the garage; they quoted 2120€ for a new torque converter. At least it should be sorted. Thanks for the help!