Gap in truxedo lo pro qt

I just installed the truxedo lo pro qt roll-up cover. I have a locking tail gate however I am able to put my hand through the opening shown and unlatch the cover. I am going to assume that I have done something wrong even thou the instruction are clear. If anyone has this type of cover could you please point out where I went wrong as mine looks like it sits to high (which is impossible to get wrong with the hardware they provided). Thanks in advance.

 

I don't have that exact cover but mine came with some hollow rubber weather stripping to cover that gap.

 

try loosening the rails that the cover mounts to down as far as you can u might have to mount every thing roll out the cover crawl inside and pull the rails down and tighten them in place mine sat very snug on the tailgate hope this helps