It’s quite possible that your wink hub and your smartthings hub are on different zigbee channels. Making one more subject to local interference than the other.
Unfortunately, if you have the V one smartthings hub you can’t reset the zigbee channel at all, and if you have the V2 you can only reset it by completely resetting the hub and then it’s just random which channel you get, you might even get the same one for a second time.
But that’s an engineering reason for why one might work and the other wouldn’t.