Looks like you have to explicitly read each characteristic to get the extra UUID data out. It's something that not even Nordic's own libraries seem to bother with. Realistically it's not high up my priority list to fix, as once you explicitly request the service with the 128 bit UUID it gets added to the softdevice's cache and it should then be able to recognise it.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I've filed a bug for it here: https://github.com/espruino/Espruino/issues/1282
Looks like you have to explicitly read each characteristic to get the extra UUID data out. It's something that not even Nordic's own libraries seem to bother with. Realistically it's not high up my priority list to fix, as once you explicitly request the service with the 128 bit UUID it gets added to the softdevice's cache and it should then be able to recognise it.