I guess I shouldn’t be surprised that he’s gone so deep into disconnecting and ignoring again but he’s added some new strange behaviours..ie: installing camera, closing off rooms, comes upstairs and doesn’t turn any lights on, working 14 hr days then excessively exercising as soon as he gets in, sharing our business with neighbours. Maybe this is all normal but it seems very regressive and back to the beginning. But I guess that’s all part of this.
Imagine what kind of head space one would have to be in to install cameras and sneak around in the dark of their own home. Paranoid? Suspicious? Scared? Delusional? I could add to this list, but all the adjectives point to being mentally very unhealthy. If you were to come across someone on the street exhibiting these signs, maybe they are muttering to themselves or screaming at no one, you would likely just cross the street. But you wouldn't take it personally and it likely wouldn't have too huge of a negative impact on your day. Can you view H as that person when he behaves in strange ways?
Regarding your backyard get-together, I don't know where you fall on this spectrum, but I still fall into the category of wanting to be a good wife, not make him too angry and tend to do things that look like 'nice-ing him back'. (I am working on all of this). So when I read your story, I wanted to jump in and not let you take it for one second. You deserve to have friends over in a socially-distanced safe manner and he does not have a right to infringe on your life like that. You did nothing wrong.
