PC won't boot dual channel after running memtest three times

[David (PassMark)]

Access patterns & timings are different in dual channel. It isn't unusual to see different test results in dual channel vs single channel.

Might have to replace both sticks (which is normally a good idea anyway to keep matched pairs).

[kalvinie]

I've ran memtest86 three times.

First with dual channel > results came back 2 errors
So in order to find out which of the module was faulty, did a single channel memtest, two times. Didn't get any errors from running memtests for single channel.

Anyways, now the problem is, after running single channel memtests twice, I've tried to install both ram sticks back and try to rerun memtest86 but now my windows 10 will not boot up.
Since windows won't boot up, I thought maybe one of my ram was indeed faulty? so I tried booting up using each ram stick and it boots up perfectly fine..

I've tried booting up using single module using every single channel to see if maybe mobo is faulty. But nope, it's all boosting perfectly fine. I just can't boot using dual channel now...

Any idea what's causing this extremely weird behavior?