Why does pdf text-selection only work on the right half of the page?

Question

This happens quite often to documents I have not personally created. You're ok to select text backwards from the right-hand side, and if you do not go too far, you get the entire snippet.

But attempting to select from the left-hand side (you know, in the direction text actually goes), it just selects an entire "block" the side of the page, or sometimes the height of the page but only covering one side or another.

I'm attempting to create my own document, it has an image as a background. I'm trying to put transparent text overlays on top of it with Inkscape (I do not believe that this is an Inkscape problem however, as I constantly see this with pdfs of all different sorts of provenance). It's something generic to pdfs, perhaps some basic misconstruction of the underlying data structure.

Is there any way to avoid this? A user who might want this stuff shouldn't have to perform mouse acrobatics (haha, pun intended) just to make use of it.