I started to make some modifications to the project risk log site, which included deleting some fields (such as trigger and contingency plan). After that, when I open the settings menu from the project center to access any of the links there (PWA settings, Edit a Page, Site Contents, etc.), they are not responding. But, if I access a page that does not have the classical experience, the menu is responsive. I deleted the project where I changed the risk log, and nothing happened.
I tried a solution where I created a new project and then deleted the Deliverables, Risk, and Issue lists. After that, I went to the settings menu (navigating first to a page with the new UI) and deactivated and activated the Project Web App Connectivity on the Site Features page. Nothing happened.