I was tying out a depreciation schedule and noticed something odd with one asset.

A truck under 6000lbs was placed in service July 2017.  Cost basis was $38,975 and took max Section 179 of $11,560 in 2017 (so depreciable basis of $27,415).  Code M2 was used for 'type of asset' on the worksheet - which is truck, van, or SUV under 6,000 lbs.

In 2018 it calculated depreciation at $3,495 and I'm not quite sure why.  The second year auto limit for trucks/vans placed in service in 2017 is $5,700 so it is not hitting truck/van auto limitations.  It is a farming vehicle so using 150DB method but by my calculations it should still be much closer to the auto limitation.

Is it possible there is something going on with ProSeries depreciation calculation?  Is there maybe some component to the equation I am missing?  Any advice/help would be appreciated!