I think I see what its doing now. You are trying to take the vacation on the 5th and 6th and expand to the Rday on the 13th. It won't let you because of the buffer between vacation and your last R day that would be remaining (the 4th). Since you waived that though, I think it should let you do what you are trying to do. If not, then you may have to start on the 4th, expand to the 5th and 6th and then just drop the R day on the 13th after open time comes out.

Either way, I'd give them a call on Monday and they will be able to explain or fix it even after the conflict window has closed.