That is odd. Whenever I face these kind of issues in crypto gambling sites, I contact their support via chat and they usually resolved them quickly. Did you try contacting their customer support on their site? If so, what did they say?

If they aren't responding there, Steve or some other Sportsbet rep could respond to your issue later on in this thread.

have you tried to lower the tdp to 80 first then have the oc on core clock reset to 0.
If it have become stable, you can increase the core clock oc from there little by little to find the sweet spot.

you can also add this to your .bat file --cpu-priority=3 -i 25

if you guys think this helps, ofcourse I won't refuse youre signatum donation  
BBc3Em17xcEj84fCYfxwQQ61BcipRH9eNA

In your miners bat file put pause at the end and sumit the error here

well install vcredist_x64 or vcredist_x86 from microsoft,and vc_redist.x64 or vc_redist.x86.
and install Net Framework 3.5,and Net Framework 4.5, and directx runtime from microsoft

Check your power.

Eth is a very low power algo.  My 1070's, without any adjustments (full stock), run it at close to 60% wattage.  Skunk is not as efficient, and your cards are drawing more power, which could be the reason you're seeing crashes.  Try lowering your tdp a bit and see if it helps.

I'm not sure if this will help,increase your virtual memory.

i have a rig that does the same, but only if i solo mine, if i mine to pool uptime is fine, stable, are you soloing?
My rig that crashes is rag tag , so i figured it was just that tho :/  (x3 1070, x1 1080, x2 1050ti)
I use intensity 21 on 1070's, but solo mining i remote in, and damn the miners crashed, disappeared from the screen totally...
maybe its remoting in that does it?
i have tried the miner Sp from Discord and CCminer, same result :/