I have only done a little research, and have neither the time nor energy to dive more extensively into it, but there are some things about the NextDoor app of which you should be aware.
1. There is no way to report lead or moderator activity, and no way to identify which individual is doing which action. I did email support@nextdoor.com, but I suspect my email will either be ignored, or the address will prove to be invalid. You can not use NextDoor's Contact/Reporting tool, as that requires you to know the specific name of the individual you want to report. If you have no way of identifying who hid or deleted your post, then you have no way of reporting them with the current system. There is also no section in their limited contact form for reporting abuse of authority.
2. The information you are getting on NextDoor, when it comes to political or societal issues, will be heavily biased towards whatever those in charge of your community decide. Therefore, if you have a corrupt mayor allegedly colluding with a private citizen, as in my area, any attempts to expose or report such activity will be censored and your account will be deleted. In my neighborhood, somehow, this same private citizen is in contact with those in charge of our neighborhood, and they are working together to censor and silence many important matters in our community.
3. NextDoor does not care about the abuse of their system. I do not know what is driving the folks behind this app, but they have been approached and contact since at least 2018 with the same issues, again and again, but have chosen to do nothing about it. They should have a section in each neighborhood listing everyone in charge, and they should make sure a history of anyone taking action on a post is available to the poster. All messages to and from those in charge should be archived and saved for legal purposes. But none of these solutions have been provided. So as I said there is no way to know who to report and no accountability of those in charge. If we knew who they were and could report an improper action on a post or user, we could report them and perhaps have a change in leadership.
If you are considering using this app, I would advise that you not install it. Not unless you really need to start your own neighborhood group for something. If you have installed this app and are using it, you might consider uninstalling it. If you are in any way paying money to NextDoor, please consider cancelling all such payments, at least until they get their act together and clean up their system.
I am thinking about removing my account from the app, and then uninstalling it. I do have a group I started that I might want to see grow, but I am not sure that is a good enough reason to continue. I understand Facebook is considering similar features - if whatever Facebook does is as terrible as what NextDoor has done I'm definitely not using it.
If I decide to delete my account and uninstall the app, I will leave a review on Google Play warning others about this app.
