i am not sure weather or not youve done any changes to the game, but the issue seems to have resolved itself? it still counts it as my first prestige and give me the 5 gems, but it no longer sends me back. regardless, here is the save https://sharetext.io/b68e575b i hope it helps :)
By "counts as your first prestige", are you referring to Expertise resetting to zero? I haven't released another update since your previous comment.
In any case, here's the save with the Diamonds refunded: https://sharetext.io/0177d9e6.