I was testing the game on your demo site out.

Came across an opportunity to split a pair of 7s.
I had 0.00000070 in my account (from bonus).
My original bet was 0.00000035.
When I split, it doubled my bet and took it to 0. (expected)
One set of cards won (see pic below) and the other lost. However, the game gave me an overall loss and didn't return any winnings.

Expected: wins/loses should be calculated on each played hand in a split. Not overall.