m15 R6, Problem Upgrading RAM

Greetings all.

Can someone help me with upgrading or expanding the RAM capacity of my Alienware laptop with "retail" memory sticks?

I own an Alienware m15 R6 laptop since 2021, and it's functioning perfectly (at least hardware-wise) to this very day. It's original setup includes 16 Gb of RAM - two 8 Gb DDR4 3200 sticks (Dell/SK Hynix), in two SODIMM slots.

My rig currently runs with Windows 11 Pro 24H2, and BIOS version (at time of writing and during the occurrence of the issue) is 1.39.

Very recently, a pal of mine got two Crucial 16 Gb DDR4 3200 sticks that he didn't need; they're new, unused (part number CT16G4SFRA32A for both). Thinking I can upgrade my m15 R6's RAM, I checked for compatibility and from what I gathered, the Crucials can be used in my rig. So I took them from him and proceeded to replace the Dell original RAM sticks with the Crucials. 

When Slot B was occupied by either Crucials, the computer and Windows won't boot or start up properly. With one stick (Crucial #1), the laptop entered Windows recover. With the other stick (Crucial #2), the laptop did not boot up, with the power button blinking red (in groups of two blinked).

This would happen with either Crucial stick in Slot B, and the other Crucial stick in Slot A; or one of the original Dell sticks in Slot A. Also will happen when a Crucial stick was in Slot B and Slot A empty.

The laptop and Windows started up normally when Slot A was occupied by either Crucial stick, with Slot B empty or occupied by one of the Dell sticks.

To summarize:

> Slot A: Crucial, Slot B: Empty = Normal startup into Windows
> Slot A: Crucial, Slot B: Dell = Normal startup
> Slot A: Crucial #1, Slot B: Crucial #2 = Power button blinks red
> Slot A: Crucial #2, Slot B: Crucial #1 = Windows recovery
> Slot A: empty, Slot B: Crucial #1 = Windows recovery
> Slot A: empty, Slot B: Crucial #2 = Power button blinks
> Slot A: Dell, Slot B: Crucial #1 = Windows recovery
> Slot A: Dell, Slot B: Crucial #2 = Power button blinks
> Slot A: empty, Slot B: Dell = Normal startup

When I run a memory test when BIOS prompts me upon detecting a change in the RAM setup (with a Crucial #1 in Slot B), I'll get the result of "Memory errors detected. Limit exceeded. additional errors will not be resolved.". The test will be all okay with either Crucial in Slot A.

Hence, Slot A is "accepting" either Crucial stick, even in combination with one original Dell stick in Slot B. But Slot B will always reject the Crucials, with differing behaviors between #1 and #2 during startup.

Now, I'm back to using both original Dell sticks, and my m15 R6 is working just fine like before I start tinkering with the RAM sticks.

I hope someone can at least explain to me what's causing Slot B to behave that way, and preferably help me overcome the situation, if possible.

I am not very versed in firmware technicalities.

Thanks in advance.