Hoa Board Refusing To "accept" Resignation

Location: Illinois

Hi, my partner was the treasurer for our 9 unit HOA. He resigned with a month notice, and the remaining two board members did not attempt to schedule an association meeting until 3 weeks into the notice period. The meeting didn't end up getting scheduled, and as of yesterday he's no longer in the position, but no one has been voted in as the next treasurer. Per our bylaws, a board member's resignation doesn't require any approval, and if there's no one voted in to replace them, the remaining two board members either have to assume the responsibilities in the interim or appoint a temporary replacement until a vote can be held.

They're not doing that, they're basically pretending he's still the treasurer and refusing to accept any of the responsibilities. One of them is ignoring everything entirely and the other is sending very erratic and angry emails. I tried to drop off a couple boxes of treasurer documentation yesterday and they both refused to answer when I knocked on their doors even though I could hear that they were home.

What should my partner do? Does he have any liability? What's his responsibility from here? Can he force their hand in some way? The boxes contain blank checks for the association's bank account, so don't feel good about leaving them unattended at their doors, but feel like they're assuming if they can make him keep the boxes they can make him stay in the role, which is not happening. We know he is already legally no longer in the role.

Eta: thanks for responses! Think I'm good here now. Yes yes not living here anymore would be ideal, but we'd like to make this work for a few more years. It's not lost on us that all other treasurers have lasted an average of like 1-2 years, likely for a reason. It's been nothing but personal attacks since my partner joined the board, including accusations of him having a "suspicious agenda" because he asked for receipts. Changes are likely needed but we're not going to be able to be the ones to make those changes. Our intention is to see how the coming months go and then reevaluate in the spring whether we would like to stay. That's not what I'm here for advice on.