I think this happens when you've 'put up' with things for years (maybe they didn't seem such a big deal or you didn't notice it so much, or perhaps you felt the other person was pulling their weight in other ways, or you had more time than them so you just did it.
Then something changes - a child moving out / being together more often in lockdown, or one person becomes busier through work for example. And you notice. You notice the small things that are just lazy or thoughtless. And once you've noticed them you can't un-notice them. And you even start looking for them. You notice you're picking up after another adult and you resent it. It could be they've been acting like this for years, or maybe it's got worse recently. But you realise it isn't fair.
So you mention it. You keep mentioning it. The other person, who is acting just like they've always acted, sees you've changed. They aren't doing anything different but you're now 'nagging' (hate that word). They feel picked on, a victim. Why are you so picky and angry these days?
So then you're both resentful.
You are raising perfectly reasonable points. Is there any chance of having a reasonable conversation, in a calm happy moment. Say you can see they don't like being criticised but why, as a grown adult, can't they put things away? Why do they think you are there to run around after them? You don't want to be constantly criticising, but nor do you want to spend your time running around like you would with a toddler.
If he still won't listen, then it may be that he simply doesn't respect you or your time. Which is a whole bigger issue.
By the way, with regard to the WFH thing. I can see how that happens. Having to go outside to your office on a cold and wet winter's day, when you could stay in the house, I can understand. Me and DH have an 'office' but on colder days it never gets properly warm and we work elsewhere in the house. I don't think it's fair to ban the WFH person from certain rooms, if there is a good reason for them using it.