My Galaxy Buds+ started having an issue recently where the left earbud wouldn't connect with the right. It turned out that the left earbud wasn't charged when this happened even though both earbuds were inside the charging case. Today I saw that my case battery was at 1%, left earbud at 46% and right earbud at 100%. I believe this is an issue where the left earbud is constantly draining battery even when it is inside the closed case. Another thing to note is that after the left earbud loses all charge it is a huge pain to get it charging and synced up with the right earbud again.
I am having the same exact issue. I'll clean the contacts and see if that fixes it, but I wanted to chime in because I'm hoping for an answer if that doesn't work.