adobe indesign - Why is there a single line of blank pixels between my touching shapes?

I'm working on a specification sheet for a tech company and they have a graphic that's used in a lot of their branding that I'm trying to incorporate.

It's two trapezoids that meet and form angular patters near the edges of pages.

In this design, I'm having them meet at exactly the center of the pages to form the footer.

this example is from the cover page, so it's extra large

I checked and double checked and my shapes are exactly edge to edge. No space in between.

However, I noticed that when people at the company were printing test pages, a blank line (equally probably 1 pixel or less) appeared between the shapes in exactly the center of the page.

In InDesign, I can see this line, but only if I zoom in a ridiculous amount (1600% or more).

I'm wondering if this is happening because the shapes meet in the exact center of the page.

The spec sheets are a single page design so there's not exactly a gutter.

I tried adding a stroke to the shapes, but that rounds out the point, which wouldn't match the branding element well enough.

Any ideas on why this is happening or how I can fix it?

Answer

In case anyone else runs into this problem:

Merging the shapes solved the issue. Select the shapes you need to merge, then go to object > paths > make compound paths (or Ctrl + 8).

Now there's no more blank line! (image below shown at max zoom. 3200%)