404 Errors alternating with specific page/custom post type when permalink reset

I have a number of posts, pages, and a few custom post types (with their own pages within them) in my custom theme. Everything was working great with a default “Month and Name” permalink structure, however, I started to get 404 error pages after I added a new child to a page, but the 404 errors are only with certain pages and one specific custom post type.

The problem first started with a specific page. The page loads fine, but all children of that page results in a 404 error. If I rename the slug from “save-the-lake” to “save-the-lake-2” the child pages show up just fine. However, I don’t want that, so I reset my permalinks to Default, then back to “Month and Name” which fixed the 404 problem….but, that then made one of my custom post types, and all pages within that get 404 errors even though the URL is exactly how it’s showing in the admin. Again, I reset the permalinks, and it fixes the 404 error in the custom post type, but then my “save-the-lake” children are back to being 404 errors. I can literally change the 404 errors back and forth between the “save-the-lake” children and custom post type pages by reseting the permalink structure.

Again, these are the only two areas that are effected by this issue…all other custom post type pages, and all other children of regular pages show up just fine with no issues. Does anyone have any idea what may be going on and a solution?