No, I don't think the bath is a problem, it's actually relaxing for most babies.
This is just a though, but bare with me for a moment.
You say that you feel like you are chasing A times all the time, and it's true - babies A times change and needs tweaking now and then, but I am thinking that because you see no results for such a long time perhaps there is something else. Do you think that maybe it's better to just stick to what you are doing now for a while, for a few weeks? It will take the pressure off chasing the A and will give him time to settle into the A times he is doing now, which seem to be age appropriate.
Maybe the constant changes in the A is too much for him?