Maybe they just don’t make em like they used to?
They don't make em anymore, period.
There are so many 'dead battery' post on the forum, a search will bring up many techniques to
possibly wake one or more up . . . these are techniques supported by DJI, as the batteries can go into deep hibernation if left on the shelf too long.
Lots of different ideas and mixed results can be experienced, so you just have to try the different techniques and see if any work.
I have read that they need to be left on the DJI charger sometimes overnight or longer, and very often see only using the cord direct, not the 4 battery hub, to charge.
Of course, as the battery is not known, leave somewhere really safe to charge, you won't be nearby that long to watch over it.
If I can't be in same room as the (normal) batteries when I'm charging, I use a large thick walled ceramic baking dish, place this on a larger oven tray, and put outside under cover.
If you aren't going to fly for a long period, like a whole winter and shoulder periods, you need to take them out and check level with a quick button press every say 2 months.
Self discharge takes them down to around 50% - 60%, but they do still keep losing a little charge over time, or they can hibernate as designed.
You can turn them on and off again even, might reset any inbuilt hibernation thing from happening, leaving 50% in them will do no damage through a long period of non use.