Based on those responses it does seem like something may be wrong with your gripper. As above, I’d recommend contacting our support email to sort out the next steps from here 
I appreciate the transparency on what you’ve tried and the corresponding results - it’s helpful for attempting to diagnose any potential issues, and make suggestions that may help fix them
In a similar vein of transparency, I thought it worth letting you know that intentionally exceeding the electrical specifications of a product to see what happens, before collecting and providing evidence that it wasn’t working properly beforehand, may damage your case for a potential warrantee claim.
That said, I’m not saying it won’t be covered under warrantee, and it’s not my call to make. If we provided you with a faulty product then that’s something we should rectify, but that will be sorted out via the support email - returns, replacements, and refunds aren’t handled via the forums.
By the way, selecting text in a previous comment/post should come up with a “Quote” button that provides the nice quote formatting (and linking).
I can recommend having a look through the How to Use the Blue Robotics Forums post - there’s been a lot of effort put into making it helpful