Hi Ho,
Thanks … I didn’t realize that you had purchased your mattress that long ago.
If there are no obvious issues with your latex layers there are a couple of things that may be worth trying.
The first thing I would try is putting your mattress on the floor to see if it makes a difference because the flexible slats under your mattress could be part of the problem. There is more about the pros and cons of flexible slats in post #2 here.
I don’t know what you are using on top of your mattress but I would also check to see if any mattress protector or mattress pad is affecting the ability of your mattress to contour to the shape of your body.
I would also consider changing the zoning pattern in your v-Zone to see if an alternative arrangement is a better “match” for your body shape and weight distribution. They also have replacement v-Zone sections available with different firmness levels. There is more about zoning in post #11 here.
It may also be worth considering putting the 44 ILD layer above the 30 ILD layer to see what difference this makes as well.
You could also replace the 30 ILD layer with a slightly firmer layer but I would work with the other options that you have available first to see if you can resolve the issue before considering buying a new layer.
Finally upper body issues can often be resolved with a different pillow.
Phoenix