Ah so it’s not an actual bug in your code but VSCode acting up. I’m assuming you have the C/C++ extension installed from Microsoft.
Not sure about a proper solution, you could try to write the full path to one of them and see if that fixes it.
There are ways to tell intelliSense to ignore errors on the following line. If nothing else, you could try to do that. It would probably be an annoying solution, as you’d have to do that with most includes, but it does get rid of the squiggles.