That's a weird one for sure.

Try what Maysik says and reverse everything, although it seems strange because you've used 2 sets of hinges with the same result.

There's an answer for sure, we just need to work it out!!!!

Hinges can be a pain, take bonnet hinges for example..... The more you think you have to adjust them one way, it's actually the other! So try pushing the tailgate hinges towards the back of the van instead of the front. Something real simple is going to be the answer.

Keep trying and resist the urge to bend anything because that IS NOT the answer!