Having just visited...
His ears are floppy, but not hound-floppy or even beagle-floppy. They don't hang below the bottom of his neck.
This started under his chin, probably in a lymph node. His ears don't show signs of mites, and Tami would know mites. I didn't get a super good look at his ears because 1. he's not my dog, 2. he starts shaking his head when Tami messes with his ears, and 3. they're gooey.

His ears, when I saw them, looked free from everything except goo, so it's draining from inside. The aroma seems to indicate some sort of infection, including fluid trapped inside somewhere. If it were me, it would be a sinus infection, but it's not me, and my ears aren't as floppy as his so nobody would know.

He's still as social as ever, but he's dialed the usual dog bounciness way down.

I know you didn't ask for folks to try to out-diagnose your vet, but we can't let any mystery escape un-molested.

Hugs.