I work with three other colleagues on my team in a new job of two months.

I work with three other colleagues on my team in a new job of two months. I am more senior than them but we report into the same manager, my manager wants me to lead without authority on major initiatives the team has taken on and that is totally ok with me. My biggest challenge is how these three colleagues work. They don't show up to meetings, they can't attend group calls last minute but do not notify everyone nor propose a new time, they don't respond to emails so people are chasing me then I have to chase them. On multiple occasions I have spoken with them about this directly, and they shrug it off like they don't have time to attend or respond. This is the most unprofessional team I have worked with. But if our manager is on any calls, copied on emails, it's like magic, they show up, participate, respond timely, etc. I've spoken to my manager about what may be going on with them too, and she said she has noticed behaviors and is addressing them. Due to this and among other reasons, I have realized this role, company and team is not a good fit for me after 2 months, or maybe vice versa so I will be resigning in a couple of weeks here for another offer. I really like my manager so that is a bummer, but she alone isn't enough for me to stick around. So the question to you is, any advice on whether I should be open about the environment of this team to my manager when I resign? I am torn that maybe it's none of my business since I am heading out, but I hate the thought of someone else coming into this environment and experiencing the same things as I did. Thank you.