Galaxy Automatic Transmission Implausible Shifting

I also own a Ford Galaxy, though I haven't had the undervoltage issue directly causing transmission problems. However, those symptoms sound very similar to what I experienced when my transmission fluid was severely worn. Have you checked the condition and level of your transmission fluid? When was the last time the fluid was changed, if ever?

Thanks for the quick response! I haven't checked the fluid myself, to be honest. I was leaning towards an electrical issue. How did you confirm it was the fluid? Did you notice any specific color or smell?

Well, the slipping was pretty pronounced. But it was a workshop that pointed to it. Initially I thought the worst, that the whole transmission was failing. However, they checked the fluid and it was dark, almost black, and had a burnt smell. Definitely not the nice red color it should be. So, I would strongly suggest that you go to a trusted workshop before you cause serious damage to your transmission.

Understood, thank you for the advice. I took it to a workshop as you suggested and the mechanic confirmed the transmission oil was worn out. An oil replacement fixed the issue, and the total cost was 240€. Appreciate the help!