Importing folder only imports some assets

When I drag in a folder that contians more than a few clips into Premiere it is only importing a portion of the folders contents. Example: I have a footage folder containing 20 clips and when I drag it into premeire only 7 of them actually import. Same happens if I right-click import. The files are fine and I can just drag them all at once into a bin just not as a folder.  So when I drag a folder stucture in I have to go through each folder and make sure it actully imported all of the contents.