If the owner is searching by city, or even zip code, the results won't exclude you if your service area includes any part of their specified location. So if someone searches for Denver, you'll show up because you provide services in Denver, even if your range doesn't cover the entire city. If someone has their profile completed with their address and requests a travel sitter, you should not appear in the results if that specific address is outside your range. Essentially, they'd rather have false positives than false negatives, where they may exclude you from the search results when you should have been listed. And while it's frustrating to get requests that aren't within your parameters, it would be worse if you never got requests that were in your parameters at all because the algorithms were more conservative in how they show results.
Once someone has gotten to your profile, there's nothing preventing them from sending a message, even if a component of their request (like the service area, dates, or size/age of dog) is in conflict with your preferences.
I have been getting that too. Seems the area people are asking about has no other sitters.