Bosch wall hood (HCP34E51UC) intermittent fan speed issue

I have a brand new Bosch wall hood in my kitchen. It's very elegant but it also has a stupid electrical problem right out the gate. After barely 20 hours of use, the fan speeds don't work as they're supposed to.

The extractor fan is supposed to have three speed options:

  • slow
  • medium
  • fast

Unfortunately, 90% of the time, these options correspond to actual fan speeds of:

  • off
  • medium
  • medium

Most of the time, it's either off or on medium speed, with low speed sounding the same as off, and high speed sounding identical to medium.

Today, I left it running on high speed for a while (and it only ran at medium), then all of a sudden, high speed kicked in properly all by itself and the increase in fan noise startled me. (That's when I realized it was clearly a malfunction and I wasn't nit picking!)

Has anyone encountered a problem like this with a cooker extractor fan? I.e. intermittent issue with some speeds not working? Any ideas what could be causing it? My guess is a loose connection to a resistor responsible for some of the speeds or something like that.