Agreed about over-watering maybe being part of the problem, the leaves do have a bit of the “bloated” look.
5-1-1 is also probably not helping, that is awfully high in the nitrogen compared to everything else, and this is by no means near a ideal NPK ratio for cannabis, not matter if it is in a veg nor in flower. Some of what is in the soil might buffer a little of what is too much and make up a little for this fertilizer’s short comings
And I know I sound like a broken record…but what is the pH? It could be some deficiency lockout due to pH.
Certainly the type of yellowing, the way it is bordering the leaves and the pattern, this does seem to point towards a possible potassium deficiency, this could also be pointing towards possibly sulfur or magnesium deficiency as well. Over watering alone can contribute to a calcium/magnesium deficiency.