There is both rhyme and reason, but some are far better than others. I have periodically worked in this arena for twenty years or so. That does not make me an expert, but I do have some clues.

For international travel issuers that have lots of international activity are far more likely to have algorithms that consider international issues. Thus, say, Chase, American Express and Citi are much less likely to abruptly freeze an account for overseas activity than are those with much less, such as, say, CapitalOne, Bank of America or SunTrust. Those are generalizations and the algorithms work in specific, so please don't give examples to the contrary because... nearly all the algorithms work almost entirely on pattern recognition. Thus, if you regularly charge in Kazakhstan and Latvia for expensive hotels and travel charges, then suddenly have a $15 transaction at Home Depot when you've never had one like that before, Home Depot could easily be rejected, more likely, the second small US charge, because most of these algorithms lag one transaction.

It is dangerous to generalize, for sure, because individual situations do vary greatly. I personally have quite inconsistent use patterns, but almost all my use is in fairly strange places for the typical card user. Only cards issued by Chase and American Express have never caused me problems (I never worked on either of their purchase control systems, maybe that is why ) Despite that I use neither of them now.