THAT IS TERRIBLE DEFAULT BEHAVIOR. I don't know how else to drill this.
You should NOT assume that everyone is going to get charged a tax and then figure it out later.
This is honestly so stupid, it's about to push me back to Hikashop. How do you guys not get that you should not be showing incorrect prices to people? Your guest checkout always seems like an afterthought. Btw, in one of your recent updates, States no longer show up on the order page. I get name, address, city, zip.. no state. I look up in the database, get a code and have to cross reference it to the state table OR google the zipcode. BTW, try out darkmode some time and see how many hard coded css lightmode things yall have; it's awful. Sometimes, it really feels like amatuer hour here.