Powerbeats pro left earbud doesn’t charge reliably in case

I’ve gone through two different Powerbeats pros. Both of them have issues with the left earbud not charging inside the case. Often times, as soon as I close the charging case the left earbud unseats from the charging contact points. I’ve made sure that both headphones are properly seated before the case is closed.

how can I resolve this problem. I’ve already tried resetting the case on both sets of headphones.