That article was much more informative than I thought it would be, there's some interesting background on previous public research on the topic of microwaves, but what was completely new to me was the fact that such cases go back decades.
Slight off topic, but I do see a bit of a parallel between medical teams claiming that those are psychogenic illnesses and the way "long covid" has been considered by some practicians. There's a bit of "if we can't measure it, you must be (unconsciously) making it up". It's rationally convenient.
In the "Havana Syndrome" case, the article claims that some blood markers have been found recently that correlate with brain damage (as long as measurements are done immediately), which certainly helps. But the mix of secrecy inherent to diplomacy and classical governmental bureaucracy makes considering it psychogenic a very satisfying solution to push the problem aside for years.