I have no idea whether it is just me having this kind of weird situation.
I find that whenever the RH tone production seem weak ( low volume ) and thin ( and I try to figure it out why and it seems overwhelming with angle of attack, nail length and shape and posture ) all sort of things comes to my head like blind man
then I take the time thinking what makes me produce good strong tone before.
and it was because I practice with some cloth under the string to mute it like 70-80 percent of the vibration. I find that I have to really pluck the string stronger naturally and more focus on my fingers to really attack the strings not just pass through them.
After 15-20 mins, I take the cloth off, the tone become much clearer and fuller with more finger confidence over the strings.
the weak sound may come back again after 4-5 days then I have to come back to this exercise again to get the feel.