@cklasik nonprofits/charity workplaces can be some of the most toxic workplaces to be employed at. I speak from personal experience. I've worked at nonprofits/charities my entire career, and every single one had some level toxicity (aside from one). To a certain degree you can manage how you let the toxicity impact you. All of my peers also work at nonprofits/charities, and it's not just me, it's their experience too. Perhaps because of the low pay, or who knows, it breeds poor work behavior. In the field they tend to produce good outcomes, but in the office, the infrastructure can be toxic. I branched beyond nonprofit and have found many not toxic workplaces, and now I run my own business, which I try to maintain an open atmosphere for.

My suggestion would be to tell senior HR at your exit interview, but I don't think anything will change if you tell them before you leave.