Earbuds: left bud not working and heating in the case

Hi, my left earbud stopped working today. Worked fine in the morning, in the evening the left wouldn’t connect. There was no evident incident or damage.

The left one is not blinking LED, no making any sound. What is strange is that the battery’s case drained very quickly during I tried this and that (reset several times).

At the same time the left earbud heats up quickly while in the case. I don’t dare to put it in overnight.

Seems like a physical damage, but I wouldn’t know any trigger for that. Perhaps somebody here has experienced something similar.

Thanks, Hendrik