RC Travel Order Question

Recently, as a Reserve Component Service Member, I received orders to attend a four day course with travel days on each end of the course. The course location was just under sixty miles from my HOR and twenty miles from my unit of assignment. Travel authorization was approved for six days, five hotel nights with round trip mileage from HOR to the course location.

Upon filing my DTS voucher, the voucher was returned stating that my travel authorization must match the days of my orders, i.e. no more than four days (three hotel nights) and to remove the first and last day of travel (two hotel nights and per diem) from the voucher request. Plus, I was directed to reduce milage from unit of assignment to course location (a 40 mile / each way reduction).

Can a JTR expert can provide some insight.