That's a fairly standard footing length, maybe a little shorter than some. Regardless, footing does very little to the static or dynamic spine. May increase the static spine by a pound or two, but no more. And, they only increase arrow weight by 30 grains or so depending on length and material. Remember, that there was cedar, or some other wood, there before, so you need to subtract the weight of the cedar removed from the weight of the hardwood that you replace it with to get the total weight added to the arrow. 30 grains on a wood arrow usually isn't enough to change its arrow flight much, if at all.
Check the footed areas for straightness. Smetimes footings aren't put on straight. In turn, the tapers aren't ground straight and the point is also put on crooked. Either of those can cause the arrow to act goofy. It's also possible that the footings weren't sanded down to the exact diameter of the rest of the shaft. Thus, at full draw, it has the effect of raising( or if sanded too much, lowering) the front of the arrow, messing up the relation of the arrow to the nock setting. If that's the case, will need to raise or lower the nock a little. Good luck.