Question Why did this happen? New RAM no boot

Feb 29, 2020
This is not an issue as I got it sorted out but just wondering about the why...

Ryzen 5 2600
ASRock B450M Pro4
Ripjaws V 3200 2x4G upgraded to 2x8G

So today I got my 16G kit and I installed it, first the PC lit up then reset and I had a heart attack, it began to boot and I immediately went into BIOS to check my RAM was there, yup it was so I bumped it up to 3200 MHz with the auto setting the same way I did with my 8G kit. Save and exit and then it would not post, was stuck with the fans blowing hard for a few minutes. Held the power button and shut it off, made sure it was seated properly and turned it back on... Forgot to turn on the PSU switch and heart attack # 2.
It did the reset thing again but this time I let it boot into windows without going to BIOS first and felt relieved. Reset and back into BIOS, this time I enabled XMP1 and set the speed to 3200 MHz and this time it worked properly.

I was pretty confident going in because I had no issues with my 8GB kit at all. Like I said in the BIOS I had selected 3200 MHz and kept the auto setting, it automatically enabled XMP but my voltage was still at 1.2. When I manually set the XMP1 profile on it set the voltage to 1.35.

Just wondering if anyone has info on what was going on with the posting issue? Does one need to boot into windows first before making changes?
Also whats with the voltage difference when I can achieve 3200 speeds in auto vs XMP