
Part of the reason this is happening in the story is because, if you remember, the old Chloe was looked down on and bullied/ignored by the maids in the mansion. Chloe was not respected, not only for her own mental health issues (such as anxiety, depression, lack of self-worth, compulsive liar, etc.), but also because the Duke, her husband, had no apparent interest in her. The maids figured out that she was an easy target for their frustrations because no one would help Chloe.

True, but in so many of these stories the "maid walks in at the wrong time" trope is used. Maybe you could argue for it here, but it's still crazy stupid in any story I read.
Although mother's not knocking when they enter their kids room is spot-on accurate. My mother never knocked. And everyone I talked to remember their mother's never knocked. So I could believe the "mother walks in without knocking" one because it seems to be the norm.

No I agree with you here. Regardless of if the marriage was arranged or without love, that’s the business of nobility not the lower class. They can gossip and say whatever they want about their masters, but the fact is that in those days, the “help” were invisible in the background. There was a distinct separation between the classes. Whether or not their master was an outcast, unloved, ostracized, sickly, or hated by other nobles, such behavior from the help would not only have them all fired and probably destroyed any potential of them finding work elsewhere, but also will make the entire household look back to the other nobility. What noble can’t even educate or discipline their help staff? And it’s the role of the head maid and butler who are lower class nobles that uphold this standard for the rest of the help. It’s just common sense.
So when I see these obvious “modernistic” views being implemented on an archaic lifestyle of the past “noble and help” scenario, it does annoy me.
I’ve read many things such as even looking your masters in the eyes when they talk to you could have gotten you fired, because it was a sign of insubordination. As well as, speak only when spoken to. Or standing at attention with eyes on the ground until called upon and such.
So when Chloe is being treated like this it makes me cringe a little.
Of course, if the masters are kind and loving and show grace to their help staff or get close to them then those particular help staff might feel inclined to have more authority and pride. But in cases like in the Dukes household were he seems to be very cold and business-like, therefore such loose-lipped, opportunistic, and crassness from the staff shown here would have them all fired.
But I'm sick of the trope of maid and servants randomly rushing into their master's bedrooms without ever knocking. Even in Downtown Abby that NEVER happened. The master rang a bell for the servant to come and the servant still knocks.
And there is a reason for that. As a servant if you walk in and see or interrupt something you shouldn't interrupt you could lose your job. Servants did not want to lose their positions and made damn sure to knock.
This trope is unrealistic and dumb. Can't authors please stop with it.