F71 is technically a SUDS code. But it’s basically just saying it detects friction while trying to spin. Try a drain & spin with it totally empty. Still doing it? Ok. No friction or noise when you spin it by hand though. Ok.
Unplug it. Tilt the washer back so you can see underneath. You will see a plastic round rotor with one bolt in the middle. This bolt can back out over time, and should be checked and tightened if so. If that is the case - that is the problem.
Bearing replacement would make sense, but not really if you don’t hear noise.
If the rotor bolt IS NOT loose - I would replace the RPS Sensor on the motor. Google that procedure for the Cabrio if need be. PART NUMBER WPW10178988.
Again - this is all assuming that the tub spins freely, and there is no bearing noise.
If the RPS Sensor does not do the trick - main control board(no longer available): WPW10249237.
Good Luck!