Arrow Fired From Dispenser with Fire adjacent to output not always getting ignited

Observed results:

Fire directly in the path of the dispenser ignites rockets, wind charges, snowballs, and eggs, but almost never arrows. However, a one block gap between the fire and the dispenser will consistently ignite the arrow.

Expected result:

Arrows will always be ignited by fire regardless of the proximity to the dispenser.

 

Note: This applies to all arrows types, including Spectral and all Tipped Arrows.