I’ve been on several non-profit boards. What you are describing sounds chaotic. Does this organization have by-laws or a policy and procedures manual? Usually these documents are a reference tool for operating the organization so it can work towards its mission. Every board member should have access to such bylaws.These bylaws should include meeting guidelines and voting procedures. There should also be personnel policies related to staff review/compensation.
Finally, a capital campaign is a huge deal for most non-profits. I’ve been involved in two capital campaigns and it’s not something the board members discussed “once in passing.” If I were in your shoes, I’d resign or if you are really passionate about the organization’s mission, I’d become an advocate for change and/or clearer operating procedures/guidelines. At the very least there needs to be more communication about what’s going on. Honestly, I can’t imagine a capital campaign happening without every board member knowing about it. IME the board chair is the one who approaches fellow board members and does the “ask” not a fellow board member.
Are there other board members who are concerned like you are? Maybe you could approach the board chair and discuss these issues?