Preview and permalink error

Hi, I have installed a wordpress website into a folder on my webserver, so I can build on it while my normal website is still live. A few weeks ago my site got SSL ticket so is now https. I installed the new WP wordpress after that but I’m having really weird issues with previewing pages and permalinks. I never ever had these problem with WP earlier.
– When I make a new page I can preview it fine, as long as it’s not yet published. After publishing I get a preview error that I don’t have permission (allthoug I’m administrator).
– If I try to reach a page by typing in or clicking on the (perma)link it goes to my root of the website. FI: I have my WP site installed in a folder called WP2. So https://WP.nl is my root and https://WP.nl/WP2/ is my new WP site in a folder. When I have a page called https://WP.nl/WP2/portfolio.html it redirects to https://WP.nl/portfolio.html
I really don’t understand. Im working on a windows server and got my permalinks set as well in config.php as htaccess and irff.ini