Page not found/randon snippet of code

This is really strange and I realy have no idea how to solve it being new to this still after a year ??

All my pages are no longer ‘found’, whenever I click on one apart from in the page editor they do not work, they just come up with “Page not found” in the style of my theme or just a weird bit of code

https://redrisinggame.com/

EDIT: It works logged out and in in chrome but not logged in on IE

EDIT2: Super weir but loggig ount and in made it work, but why