Did you ever figure this out? I’ve been having this same exact issue lately. I did 1 iPhone 6, 1 6S plus, 2 7Plus, and 2 8 Plus over the weekend... and every single one of them has had ear piece problems. Front camera works but the earpiece is not. I’ve never had these kind of issues before and I’ve been doing these for years. And the 7+/8+ I transfer I’ve the tape and still nothing. I’m starting to think maybe Apple is sabotaging aftermarket repairs again in this new 12.2 update.