wirless earpod battery / charging issue?

Left wireless earpod has stopped working. Message "battery low" (when battery wasn't low) followed by it not recharging and the LCD display on the charging box only shows the right side. A brand new pair of earpods which I had in reserve has the exact same issue straight out of the box, despite never being used - the left pod doesn't work and the LCD display only shows the right side.

Is there an issue related to the iPhone itself which has caused this problem? These are not official Apple earpods but are two different makes, as far as I can tell. They are paired with an iPhone SE, Model MHGT3B/A using iOS version 18.6.2.