Having a ram slot ssue with a newly purchased motherboard

Xilonian

I picked up a new asus z690 motherboard last week along with a CPU but can't the system won't post with ram in the second slot. It will cycle the cpu and ram lights a couple times before showing a solid ram light. I've tried each one of my sticks individually in slot 4 and am able to boot perfectly fine. I currently have 2 sticks in slots 3 and 4 and it runs fine as single channel. If I put in a third stick in slot 1 it also works but as soon as I use slot 2 it won't post. 

I'm thinking I may just need to get the board replaced but am open to ideas before I do this. 

Yingdong

Does A1 + B1 work as dual channel ram? If A1 and A2 both didn't work it's also possible that the memory controller integrated in the cpu has some issues. But with only A2 not working, it's likely the board's ram slot died.