Adults in a shared home consult each other about changes in routine and schedule to check it works for everyone in the household. That was your first oversight. A husband or wife consult each other, for example.
A dependent adult child living with their parents is at home, but it is not their house. It is the parent's house and they ultimately decide what works for them. Your parents have told you it does not work for them. You are not a child any longer, you're an adult. You have to respect their wishes.
You said you have tried to engage with them more in evenings and they want to do their own thing. Good for them! So common sense may have told you that an additional day in the house would not be welcome. It isn't that you are unloved, it is that they want their own time, their own space and to reclaim their non-parent identity a bit more than you are ready to accept.
You may not think about it but you will be home another day of the week, meaning more food, more bills, added disruption that thing inevitably brings. You are asking more from your parents with no consideration to what that means. I also doubt you pay full market rates or you would be living independently. Why did you think that was a decision you could make without asking first?
Lastly, I am afraid they probably see your decision and to choose to work less (weekdays) at your age as a step backwards, not forwards. A 20-something doing compressed hours, with no apparent reason other than wanting to hang around the house, probably seems like they are even further from enjoying their retirement as a couple. You don't seem to want to use the day for study for example, or maybe build a business, or volunteer. I wouldn't be happy with my adult kids being home on a weekday, under my feet, running utilities etc. That is my view, not everyone's of course, but I can't get behind the choices you want to make as a 20-something. And for me, that is why it would be time for you to move out and get a taste of living independently.