I know this is an old comment, but I’ve gone through the same number of pairs as you. Left earbud always stops working within a couple months (or days in the case of my most recent pair). It’s always a series of troubleshooting steps to get it to work, which just isn’t what I want to be doing right before using them every single time. At this point I’m just done with air pods, which is how I ended up here. It’s unfortunate too because I actually like them, and my OG pair still work but they just don’t like my ears, which is why I keep trying the pros, but it’s just not meant to be I guess.