Help with Audio Output for Audiobook

Hey All,

Noob here, but learning.

I'm recording an audiobook and am posting both video style and want to link it to my book that's for sale on Amazon.

Amazon/ACX/Audible is going me a hard time saying things like ...

Sample Rate (khz) Value: 48 File is encoded at an incorrect sample rate. Re-encode the original source audio to 44.1kHz. Read our Encoding Guide for further guidance.

RMS (dB RMS) Value: -31.2 RMS is too low. Raise the level of this file 8.2 dB. Visit Guidance Section 1 – Adjusting Low RMS Files on our Audiobook Production RMS Guide for further guidance.

A quick search told me that I needed to adjust the sample rate BEFORE doing anything else, and I did that, but for some reason I got the same error after I rendered and uploaded.

The ACX Audio Requirements are here if that helps.

I'm sure it's clicking a bunch of boxes, but I've been clicking for quite a while to no avail.

Thanks in advance.