@Mambucho want to report back that I finally solved the issue on my 4th interposer, but I belive it was not the interposer but rather the technique I was using when installing the interposer. So what really did the trick was carefully screwing the interposer to the thin connector. Heres the exact step I followed for others who might be in the same situation:
- screw the right side but dont screw in fully just until it fits lightly
- screw the left side in fully (slightly more than the right side)
- screw the right side in slightly more
I can confirm that the above did the trick because when I attempted to screw both side tightly it threw the 4 white, 2 amber error and when I did the above step it started detecting the RAMs again. The key is to NOT TO TIGHTLY FIT the screws holding the interposer to the connector plate.
Another thing I realized is that the right side of motherboard of the laptop (not the interposer) is sligthly elevated compared to the left which could be the reason that tightly fitting the screws in could lead to some misalignments between the interposer and connector plate. I state this because the same screw sized screw that was able to screw the left side of the interposer was not able to screw the right side for which I had to use a longer screw.
Would be curious what others think about this, thanks for all the assistance !