(apparently no ELT was heard).
That's pretty common these days, especially if the ELT was 121.5. The receivers that used to hear those were fairly widespread and didn't hear that many of them on the ground anyway, most are inop or completely removed, the satellites that monitored for 121.5 aren't operational anymore, and generally the chances of a 121.5 ELT being heard by anything other than an overflying fellow pilot are about nil.
406 has a better chance but there's very little listening for them terrestrially, (all towers used to have 121.5 available to them, not nearly as many have installed any sort of 406 monitoring, and SAR groups used to privately fund 121.5 monitors in many places but really haven't done so to the extent 121.5 was covered 20 years ago), other pilots can't listen at all for them (removing a considerable number of possible listeners), so generally the new satellites are the only game in town for those.
Without a mandate to switch types and re-investment in ground based receivers at airports to augment the satellites, the whole thing isn't so much a "system" of listeners anymore as it is almost a satellite-only system.
The new ELTs do put out tiny bursts on 121.5 at massively reduced power levels. From experience trying to use them in training exercises, the 121.5 signal is pretty much worthless if you aren't standing there looking at the broken airframe. Many pilots haven't heard the sound of them and might not even realize they're an ELT in weak signal conditions. They're not nearly as obvious as an alert or alarm type of signal as the old sweep tone on 121.5.
^^ All that to say... Not hearing an ELT these days isn't much of a surprise at all. 121.5 ELTs are pretty much worthless at this point and 406 aren't far behind unless they're hooked to a GPS location source AND the satellite decodes the location. Most ground-based monitors have no ability to decode the data burst. The few that do are orders of magnitude more expensive than a simple receiver, and therefore economically, there's always going to be far far fewer of them listening.
If you really want someone to know right where you are or as close as they can get to start a search, get a Spot. Secondarily in importance, IMHO, is an upgrade to 406 and pay to have it GPS interconnected.