For those on the line, or about to be...
I had off every weekend in September. I am working EVERY weekend in October. I had to double check my bid to make sure I didn't accidentally hit award weekends.
I suspect it is because we started the 6 on, 2 off (unless waived). I emailed the scheduling committee to try to get some more SA. Hopefully the grid is green and I can move some weekend days. Even when I was brand new I got at least 1 or 2 of the 8 weekend days.