GA-X58A-UD3R triple channel ram not recognise in windows 10

[The Joker]

I am having some problem where I have 6 GB of ram in triple channel slot on my board GA-X58A-UD3R (rev 2.0) but it can detect 4 GB only in the bios test

when I check the ram in cpu-z it is showing that all 3 slots are detected ie 6gb

I also checked in task manager and it is showing only 4 GB total + 2 GB hardware reserved.

I checked each individual ram stick in middle ram slot and it detects all ram sticks so I don't think the ram is faulty
I also cleared the CMOS

[shadowsports]

Greetings,
Is your RAM (matched) triple channel kit from the same manufacturer and on the QVL for your board?

There are several possible reasons / solutions for this problem.

Faulty RAM
Using unmatched DIMMs
Incorrect BIOS settings or SPD Detection
Not using RAM on the QVL for your board

Possible ways to resolve:

Replace RAM
Set RAM timings manually
Use only QVL RAM
Flash BIOS to earlier / later revision

[The Joker]

Greetings,
Is your RAM (matched) triple channel kit from the same manufacturer and on the QVL for your board?

There are several possible reasons / solutions for this problem.

Faulty RAM
Using unmatched DIMMs
Incorrect BIOS settings or SPD Detection
Not using RAM on the QVL for your board

Possible ways to resolve:

Replace RAM
Set RAM timings manually
Use only QVL RAM
Flash BIOS to earlier / later revision

Yes the ram is QVL ram
since I was able to get 6gb in triple channel previously since I have owned this motherboard 5 to 10+ years ..

I just tested with a different lot of ram that I got that I know all works
and it seems like from the testing that ram slot 1 and 2 is faulty and not reading that ram stick in that slot in the BIOS.

So when I go into channel A there is no SPD auto configuration detected for that ram stick in slot 1.

I tested with my other 6 gb ram and that same thing occurs..

So is there any way to fix the slot 1 and slot 2 on my motherboard?
Not sure what has happened but those slots seems to be faulty..

I also manually also set the SPD for that ram stick but windows will not boot and I get alot of really long beeps..

Also despite the slot not seeing that I got a ram stick inserted..
and the bios not recognize that ram stick in slot 1 etc.
when I boot into windows, it is showing that there is 2 GB hardware reserved ram..and 4 gb total ram
ie 6 gb ram total

Also CPU-Z shows that slot 1 does have a ram stick inserted and with the correct SPD information as the other ram sticks in slot 3 and slot 5

So what else can I do to fix this problem?

[shadowsports]

Greetings,
As I said there are a few possible things to try.

Given the length of time you have owned the board, I assume all slots worked at one point in time?

What changed?

Did you upgrade the BIOS?

Have you tried setting the memory timings manually?