Hello, This happened to me today, on a provably fair Dice Bitcoin gambling site I lost some money, then I checked my bets using an online verifier, in their website they say they use SHA512 algorithm to hash server seed, however, when they revealed the unhashed server seed I checked it using a SHA512 calculator... It should match the hashed server seed they provided to me, however, it does not match.
The problem is that how do you hashed. Sometimes, people insert seed in such way, that it considered by the program not like a big number, but more like string, so results will be different for each type (number/string). When i started my programming on Python, this often happened to me.
So, are you sure that you don't fall under the same mistake?