The article does not discuss the cases that were happening outside of Cuba.
Other countries include China, India, Switzerland, France etc.
Here is an article about some Europe cases:
https://www.bbc.com/news/world-us-canada-59986297
I consider this matter unsolved but I would not rule out side effects from our own high tech listening devices inside our own embassies.
If the technologies are secret and compartmentalized it would be kinda difficult for .gov to fess up....
Mass hysteria. Monkey see, monkey do. State Dept embassy types hear about the Havana Syndrome and that people are getting disability retirement. Some imagine symptoms... some cynically know it’s like back pain in the workplace. Exceedingly difficult to disprove.
Claim headaches, confusion, dizziness, etc...
Havana hits everywhere.... It’s a scam.