After Effects won't allow me to change Audio Codec (quicktime format)

Just to add... Why did they remove the ability to export to H.264? I think it's becoming a legacy codec but still - if media encoder can export QT with different audio codecs, as well as export to h.264 - then why did they remove it from AE?

If they want us to only use media encoder then they should have just removed the render queue

Simple -- revert your machine to run CC 2017.

Screw 2018.  Forget it even exists.  If you have existing 2018 project files, backsave 'em to 2017 and get on with life.

AE CC 2018 A) is buggy as all hell,  B) is incapable of reading certain PostScript typefaces and C) lost support for a whole boatload of Quicktime codecs.  A real piece of crap.

"Well, Adobe's warned us they would drop a lot QT support for a long time.  You should have prepared for it."

That's what some people around this forum are writing.  They don't get how broadcasting works.  They're all blinders-on, gung-ho Adobe.  They don't understand that you have to deal with gear by 5-6 different video equipment makers on a daily basis in our line of work -- and  NONE of them are about to kiss Adobe's a**.

I happen to work at a Sinclair station.  I cut in Avid for topical promos, and for everything else I use Adobe -- CC 2017.  The Home Office has NOT approved CC 2018 for use on company machines.  You can run it on your own personal machine, but don't expect any help from the engineers.