GPS on Epix

Has anyone been able to get GPS working on a ConnectIQ app for the Epix? I'm not doing anything fancy in https://forums.garmin.com/showthread.php?259957-App-Heavenward as far as GPS positioning is concerned (simple one-shot fix on launch), but there was a report that GPS wouldn't fix on the Epix for this app. Works fine on Vivoactive HW.

Relevant code is basically as follows:
function onLayout(dc) {
Position.enableLocationEvents(Position.LOCATION_ONE_SHOT, method(:onPosition));
...
}

...

function onPosition(info)
{
latLon = info.position.toRadians();
}