A small percentage of dogs are scared of vacuum cleaners, mostly the puppy farm ones that were born in sheds or barns and then didn't sell quickly so spent some very important months without being socialised or acclimatised to everyday things.
Puppies need to be safely exposed to as many things as possible in their first few months of life and thankfully, most are.
That being said, A large percentage of dogs
don't particularly like vacuum cleaners, which is a completely different thing. Vacuum cleaners make a lot of noise, (Including a goodly amount that is beyond our hearing range) and they move in unpredictable and dangerous ways.
I hate it when Mrs Red or the girls are vacuuming, I can't hear the stuff that I want to hear and I get chivvied around the room so, more often than not, I make myself scarce.
I suspect most other men are the same.