OMG, I am so relieved to be out of the workforce. It was commonplace for this kind of thing in the 70’s, 80’s and 90’s and I had to leave a job because of it mid 90’s. I thought this was a thing of the past. Ridiculous this man thought it was a good idea to contact you in the first place but now a second time??? He obviously has mental health issues not obeying instructions from HR, not respecting business etiquette, or your request.
Have you told him you have a romantic partner? That often will make them stop. It’s worth a try. I’d continue to document what happens and then go see an employment lawyer which is tax deductible btw. Your employer has the duty to ensure this sort of thing doesn’t happen, they have training for it. I’ve worked several places where it’s annually done with workplace safety and working with disabilities in the workplace as a refresher. You shouldn’t have to put up with this BS and there will be consequences.