Sending two exposed filters fast
The problem is that because of the auto-submit, you submit an ajax request as soon as the first filter is changed. It then doesn't matter that you make a second change, and the answer to the first request is already being processed.

The only solution that I'm aware of, is to not use the ajax functionality in Views, and instead implement your own, that for example waits one second after changing the first filter before submitting the form, allowing several filters to be changed in one request.