memory training only works in one slot

[Sgetti]

specs:

mobo: msi z390-a pro

cpu: i7 9700k

ram: 8gb corsair vengeance rgb

so i tested every ram slot by clearing the cmos then changing the slot I put the ram stick in and with the ram in all slots but b1 the ez debug lights jump between cpu and dram. with the ram in b1 it boots no problem, once it initially boots I can add more ram and change what slots I put it in as long as I don't switch it to dual channel. this is the pc I don't use any more but when I did I ran 3 sticks(i mismatched a random stick I found with the pair I had) in slots a1 a2 b2. is it possible the traces wore themselves out enough to not be viable for training. I dont think it's relevant but I am missing a vcc socket pin

[Timme]

1 hour ago, Sgetti said:

I don't use any more but when I did I ran 3 sticks(i mismatched a random stick I found with the pair I had) in slots a1 a2 b2

I'm not sure that dual-channel will love mismatched pairs of sticks. 
 

 

2 hours ago, Sgetti said:

8gb corsair vengeance rgb

That is a single stick? Not a Vengeance Pro? If so, what are the other 2 sticks?

[Sgetti]

23 hours ago, Timme said:

I'm not sure that dual-channel will love mismatched pairs of sticks. 
 

 

That is a single stick? Not a Vengeance Pro? If so, what are the other 2 sticks?

the sticks of ram i have are two 8gb vengeance rbg (not pro) and an 8g adata xpg. the one 8gb stick is just what I used to test each slot. I tested dual channel with just the 2 8gb vengeance sticks and still nothing