Bear in mind XF2 is not yet officially supported and even so, we do not provide support with third party add-ons, so generally the support for installation issues would have to come from the authors.
Though, generally speaking, this would likely be file system permission/ownership issues. As you will have installed XF2 using the CLI, the files created during installation will be owned by whatever user you ran the command as, which is likely different and more privileged than the web server user.
There's some general advice here:
https://xf2demo.xenforo.com/dev-docs/#a-note-on-file-permissions