How many times you experienced this? If it’s most the time then probably they are using a bookie that has some delay on confirming the bet result. I do experience this before on some casino even the popular one but on some bets only and not exceeding more than an hour.
A delay payout is sucks which you should consider on choosing a sportsbook. Why do you use this casino despite the delay while other casino including the one you are promoting on sig space has a good sportsbook?
Twice, I've made a few other bets and the casino paid out immediately if the bet was validated. However, this is just user feedback and maybe they can check if it's an error.
I also place my bets at the casino I promote, and whenever a win is made, the payment is consolidated immediately, so I have nothing to complain about.