I am getting some strange results with finding anchors.
The functions getOrigin/DestinationAnchor works as expected with a diagram before it is saved. However after reopening the file the results are confusing. The anchor pattern itself does not change, it is always the same
I cannot find any issues with my code so far, but will continue looking.

var ilinks = node.getIncomingLinks();
if (ilinks.length > 0) {
var orig = ilinks[0].getOriginAnchor();
var apt = ilinks[0].getOrigin().getAnchorPattern();
}
var olinks = node.getOutgoingLinks();
if (olinks.length > 0) {
var dest = olinks[0].getDestinationAnchor();
var apt = olinks[0].getDestination().getAnchorPattern();
}

Apparently the anchor point indices aren't serialized at all, and the values you are seeing correspond to where the new link instance would align before loading coordinates from JSON. For time being you can reset index values from loaded link points like this:

diagram.fromJson(...);

var ArrayList = MindFusion.Collections.ArrayList;
ArrayList.forEach(diagram.links, function (link)
{
	link.originConnection.anchorPointDetails =
			link.originConnection.getNearestAnchor(link.getStartPoint(), link, false);
	link.destinationConnection.anchorPointDetails =
			link.destinationConnection.getNearestAnchor(link.getEndPoint(), link, true);
}); 

I hope that helps,
Stoyan