I would suggest you get a shop manual for that car. I have had a’50 Super since ‘75 with the same mechanism and never experienced this issue. When I lower my hood, I hear a couple noises instead of just one that tells me it is latched. It’s like you have to push it down, and then it pushes back a little, makes another noise, and then lets you know it is firmly latched. Not easy to explain the idiosyncrasy, I would hunt down another buick owner at a show and ask him for a demo. Yours must slightly out adjustment. Does it happen usually on either side, or mostly just one side? I feel you pain because four years ago my conventional Chevelle hood smacked me in the windshield at thirty-five mph due to a bad latch. At least with the Buick, only one side is going to come up and then come back down, because of no wind. Keep us posted.
Yours may need lubing, but to much lube in the wrong place can make it slip back down between the time you pull the cable and then get out to raise the hood. Then it helps to have long arms.