The November 19, 2018, issue of The New Yorker has a lengthy article about the medical problems experienced by some U.S. diplomats in Cuba starting in late 2016 (and after the U.S. presidential election). 
The conclusion, however, is the same as previously reported: some U.S. personnel did suffer injury and the U.S. Government has publicly stated it does not know the cause or perpetrator of these injuries.
But the article does provide greater details about many of the victims having been CIA agents and about the U.S.-Cuba interactions over these incidents.
 Entous & Anderson, Havana Syndrome, New Yorker at 34 (Nov. 19, 2018).
On June 4, U.S. Senator Jeff Flake (Rep., AZ) and Eric Schmidt, former Google Chief Executive and now a member of the board of directors of its parent company, Alphabet Inc., met in Havana with Cuba’s President, Miguel Diaz-Canel. Others in attendance were Cuba Foreign Minister, Bruno Rodriguez; the Foreign Ministry’s Director General of the United States, Carlos Fernández de Cossío Domínguez; Philip Goldberg, U.S. Charge d’Affaires in Cuba; and Cuba Communications Ministry officials. Below is a photograph of Flake and Diaz-Canel.
Google and Cuba have been discussing how the company can help connect Cuba to undersea fiber-optic cables that run relatively near to the island, which would allow Cubans faster access to data stored around the world.
Afterwards at a press conference, Flake said, “We had a good meeting with President Diaz-Canel. … We are hopeful for the future if we can have more connectivity, more travel, more meetings with Cubans and vice versa. We were talking specifically about connectivity, but also about the challenges that have come up. Obviously we have had some setbacks.”
Presumably they also discussed the unfortunately unilateral U.S. Cuba Internet Task Force at the State Department that presumably is seeking to improve Cuba’s internet access. On February 9, 2018, this blogger advised the Task Force that it “is based upon false & illegal premise that U.S. unilaterally may & should decide what Internet services Cuba should have & then take unilateral steps to provide those services & equipment. Instead U.S. should politely ask Cuba whether there was any way the U.S. could assist in improving their Internet service.”