Fans won't power back on after sleep mode

[DavidHawk62]

So whenever I try to wake my computer from sleep the same 2 fans won't power on again but the rest of the system works just fine. The fans work no problem otherwise, it's just annoying to have to restart my whole system just to get them spinning again. Any thoughts on what the problem is and how to maybe fix it? Those particular fans are on a splitter to the motherboard header but so are another pair and they've never given me any trouble.