I was just given a midyear raise. I was sent a new contract indicating the new annual salary and included in the contract was an additional 5k bonus. previously I've been told that my position is not eligible for a bonus so I reached out to my boss to confirm it was correct. he said it was… all other parties had already signed the contract. I signed last and returned it. now I'm being told that the bonus was a typo, and my boss is working with hr to see what can be done. he says he's on my side… what should I be doing in this situation? can I fight them taking it back since the contract was already signed? if it's relevant I'm in the USA