Any C++ Breaks Any Project might have relevant information to help your problem. You can find tons of other posts like this around the web dating back years. So no, this isn’t some new issue people have.
Also, make sure you’re upgrading projects correctly. Not all of the cvars carry over correctly, if things about them change or if some of them end up depricated. It’s always best to just create a new project, set your various settings you want, then migrate assets over(they’ll copy over any dependencies they have). You can usually just select your levels and migrate them and they’ll pull everything over.