Replace WordPress install with new one

Hello,

I have a WordPress site but my theme has some display bugs. I would like to make a fresh new installation of WordPress, with same theme, but on a clean install, on I would like to copy-paste all posts and pages from old to new install with same URLs.
I will configure the new site on another server and then remove all content on the first server, and move the new files on it.

I would like to know if this can affect the SEO of my wordpress site??

Thank you in advance, any help is appreciated!