First generation Apple HomePod hot and multiple popping noise

On the latest firmware 18.1 my HomePod got hot and started making popping noises until it shut off completely, I unplugged it, let it cool down and moved it to another outlet with a factory reset. Works without problems, but there is heat present at the top of the case, not as strong as it was, slightly warm. Any thoughts on that? Why is it warming up?