I had this problem with my blazer. I had some one hold the release out and i gently tapped the hood above the latch with my fist. It popped open and i lubed it with white lithium grease and have had no trouble
Tried this but it didn't work. The release will pull out and stay out. Nothing releases at the latch. Still can't get the hood open. Thanks for the suggestion though. Found that you can remove the hood latch from underneath the car and then detach the latch from the hood. Time consuming but it worked.