What is the default method of FindClusters?

Question

I used Method -> Automatic on FindClusters and obtain a cluster autoCts as below:-

BlockRandom[SeedRandom[12]; rand = RandomReal[1, {30, 2}]];
autoCts = FindClusters[rand, Method -> Automatic];

Since I was using Method -> Automatic. I want to figure out what is the exact method that I was using in FindClusters. As per the documentation, there should be 10 methods except the Automatic. Thus I plugged in all of them to see if I can get the same result:-

allMethods = {"Agglomerate", "DBSCAN", "NeighborhoodContraction", "JarvisPatrick", "KMeans", "MeanShift", "KMedoids", "SpanningTree","Spectral", "GaussianMixture"};
allCts = Quiet@FindClusters[rand, Method -> #] & /@ allMethods;
checkSame = (# == autoCts) & /@ allCts

As you can see, 7 methods give a different output (i.e. False in checkSame), while 3 methods don't give an output.

How can I determine what method I was really using in FindClusters?

Many thanks!