- Espressif-IDE V2.5.0
- ESP-IDF V4.4
- I created a totally new project with its own unique name (choosing not to use a template for now). NOTE that this project had similar unresolved inclusions!
- I built this project, which had only the default lines, and it took a while to complete. After it did, the unresolved inclusions were gone.
- I closed this project, and I also closed Hello World since it was still in my project explorer.
- I closed the Espressif IDE entirely
- I reopened the Espressif IDE, and now BOTH projects seem to work totally fine, with rebuilds and such, and the unresolved inclusions do not show up anymore.
Hopefully this information helps someone else.