Russia says they've been working on "psychotronic weapons" that sound very similar to Havana Syndrome[1]. Nobody in the mainstream media believes this is real though. Since the consensus seems to be that it's not real, they will never ever get to the bottom of it, at least officially. BTW, this all started after a whole bunch of mysterious deaths of Russian diplomats.[2]. What I think is going on here is that there's some spy war that involves weapons that the people conducting it would rather the public didn't know about, so they are dancing around the issue and act like they wish people would stop asking about it.
[1]https://www.nbcnews.com/science/cosmic-log/reality-check-rus...
[2]https://www.independent.co.uk/news/world/europe/russia-diplo...