Yes and yes. The lower leaf yellowing, like yours, is generally a nitrogen uptake problem. If you're pH is below 5.5, you may want to raise it a bit to allow for a bit more N uptake. Otherwise, add a shot of N, but remember, once the lower leaf has lost it's color, it won't come back. It should add darkness to the green of the younger leaves and new growth. Last, any commercial soil company can have an off batch/bag that has to little or to much of some of the additives they mix into their recipie. Doesn't matter if it's FF, Roots even SunShine Mix, any of them can have a poorly mixed batch.
Hope that helps,
N2