WU has a sending limit of $3000 per day as far as I know. $2000 should be fine as I've sent amounts greater than that a few times.
Did you do the transfer online or by going to a WU location?
I've received amounts up to $2500 in a single transaction with MoneyGram so I'm quite sure their maximum amount is way more than $900 per transaction.
My first $2k transaction was a few days ago, it got denied after the sender already funded, but before I picked up. The problem was on his side, where the agent decided to reverse the transaction because they suspected the sender was funding terrorist activity (wtf right??), so WU called him to go back to pick up the money. At the time I posted, I wasn't sure if WU had sending amount limitation or something the sender did to trigger the suspicion.