The completion date is incorrect due to the failure to exclude days off

Hi everyone,

I have a work schedule as follows: August 22nd is a time-off, August 23rd-24th are non-working days. The schedule mode is Fixed duration, and working hours are from Monday to Friday each week. However, when I create a new project with a start date of August 21 and a duration of 4 days, Project for the web calculates the completion date as August 24, without excluding the days off (The image is described below). Can you please help me identify the issue or if there's a way to resolve it? 

Thanks ~