In March 2023, seven U.S. intelligence agencies completed a review of the proposed cases of Havana syndrome and released an unclassified report with the consensus that "available intelligence consistently points against the involvement of US adversaries in causing the reported incidents" and that a foreign adversary's involvement was "very unlikely".[2][3] This stance was reiterated in a March 2024 report by the National Intelligence Council.[22]
I still think it's going to end up as something intended to work with a passive bug, but they discovered this as a side effect and Russia being Russia immediately turned it into a weapon.
Quite an embarrassment for the US that it was first classified as not having been done by a foreign entity. Hopefully we find out additional details soon.