@Gail1066
We aren't allowed to discuss someone else's listing specifically here on the CC, only the original poster's listing. That said, keep in mind that HST tax should be applied to:
Nightly Rate + Cleaning Fee (or other fees) + Airbnb Service Fee
If a Host decides not to charge a cleaning fee, that will obviously reduce the taxable amount. As I mentioned, Airbnb doesn't always get the taxes right. Sometimes they apply the wrong TAID (Tax Area ID Number) to a listing and of course the taxes will be wrong. Sometimes they overcharge because of it and sometimes they undercharge.
If you know about an error on another listing regarding taxes, you would have to contact Airbnb about it. Be prepared for a lengthy process, as this is another listing in question, not yours. They will want your listing ID number, the other Listing ID number and screen shots of a reservation on both listings showing the taxes. Even then, all tax issues go to a "Special Team" and you won't be able to discuss directly with them. Frontline customer service will not be able to resolve this and it will need to be escalated. Get the Case Number from the frontline CS and use that in future messages.
I would try that first and see what Airbnb says. You can send me a DM if you like and I'll try to help further.