How Do I report a bug in the core audio driver?

I run Logic Pro X and use a thunderbolt device (Focusrite Clarett 8PreX). I record always use my audio interface and never change the settings. Everything used to work, after the last update I could get audio into Logic from my interface and I could monitor and listen to Logic. iTunes worked as well, but sound would not play in Quicktime, garage band, random youtube videos will not play audio in Safari, but will play audio in Chrome. I used the Midi/audio set up utility and change my settings to 192,000 Hz / 16 ch 24 bit integer and suddenly Quicktime works. It was set at 48,000 Hz 28 ch 24 bit integer and with those settings is where there is a problem. Tech support was no help and kept referring me to Focusrite before I figured out how to fix it myself. Is this a bug in the core audio driver or the focusrite driver? I have read many complaints about a similar problem with other external audio interfaces by Focusrite and they all suggest the work around I found. This problem just appeared after the last update I downloaded for the OS.