Maybe try switching then between multiple devices, using them a bit, then putting them back into the case and waiting a couple of minutes.
This seemed to do the trick for me: pairing first to iPhone, listening to an album or half an album on Apple Music, placing back into case and closing lid, waiting a bit, then pairing them with and doing the same (except maybe I watched some YouTube instead of listening to music) on my iPad. I put them back into their case and waited, alternating between closed/open lid every few minutes, but nothing. Then just as I began giving up, reconnecting them to my phone before placing the ‘Pods back in their case and then heading off to bed, voila—I checked again and they’d updated.