I think there are two things going on here. One is his controlling tendencies, which sound as though they've been exacerbated by the constraints of lockdown, so lack of control over so many other areas of his life. The most obvious answer to that is for him to recognise that he has a problem, restrain himself and also exercise outside more. It should help dampen his anxiousness.
The other thing is that you and he have different standards (values, ways of life). You could call him old-fashioned and you could look for differences in upbringing. Or both just accept that you have different values and preferences. Perhaps a surprise after all these years. Perhaps you've grown apart.
His standards are normal for my parents' generation, who see being presentable (so available at a moment's notice) during the day and evening, say 9am-9pm, as a sign of decency and a well-ordered life. This is connected to their expectation of a far more face-to-face community and social life than many people live now. The expectation that people would knock on your door in the day or evening and you'd answer. (Canvassing politicians, the milkman or window cleaner seeking payment, salespeople, carol singers, charity collectors, children casually 'calling on' other children etc). Slobbing about in nightwear or something that looks similar, having curtains closed during the day, not answering the door when you were home, would all be considered to indicate illness or a disordered lifestyle.
The habit of changing into loungewear after work is very recent i.e. last 20 years. It goes hand-in-hand with the peculiar-to-Mumsnet habit of refusing to answer your door to unexpected callers.
I wonder if it's all linked to lengthening working hours, as well as the decline of the housewife, so that people live all their public life during the working day, then crawl exhausted into their home-cave, desperate to shut the world out.