Solid inspector says shiny but part is not a solid

[lt72884]

ok, so my scale is 100 meters per mm to prevent tiny face issues, but for some reason, this part is not a solid, but solid inspectors says it is. i can not see any extrusions intersecting or missing faces. Whats the next process? How do i search for the issue on a repeating pattern?

ran it through clean up 3 and it did not find any issues

thanks

[Box]

It is probably something like the ones I have circled, where two edges come together forming a non thickness.

But without seeing the model that is only a guess.