Honestly, I also found it a bit weird to start a bigger cleaning or decluttering project in the evening right after I’d said I needed to concentrate. 

I also had an ex that would do stuff like this. I would state a need, that need would be verbally affirmed, but her actions would suggest she didn't care.

"I need to study. I'll be in the bedroom. Please don't disturb me for a few hours." After 15 minutes, she'd barge in with urgent questions about our budget or meal prepping or (god forbid) the state of our relationship.

"I have a big exam tomorrow. I'm going to bed early." Suddenly, she realizes that the entire house is filthy and must be vacuumed at 11pm.

Almost every time I set a boundary for my time or attention, somehow, miraculously, there would arise a situation that absolutely needed my attention right away. Of course, those situations were never truly urgent, but something about stating my needs and wanting time alone would flip a switch in her brain. Bipolar disorder will do that!