Sometimes I accidentally upload the same set twice because I mix up the numbers and then I adjust it and ask SC to fix it. It generally only is wrong for a day or two.
I've also done what others have said.... done a lot of one set and it goes past the maximum so I split it into two sets. I don't want it to be two sets in a row so I spread it out.
We sometimes do "Best of" sets which happen occasionally
If it happens often then there is an issue yes. But mistakes do happen, charms aren't perfect, we do make errors once in a while