When you move a layer on the timeline, keyValue() may return an undesired value.
tested with AE 2024 and Beta.
var proj = app.project;
var thisComp = proj.activeItem;
var selectedLayers = thisComp.selectedLayers;
for (var i = 0; i < selectedLayers.length; i++) {
for (var k = 1; k <= selectedLayers[i].text.sourceText.numKeys; k++) {
alert(selectedLayers[i].text.sourceText.keyValue(k))
}
}