Just fyi people who play on PO:
PO sometimes bugs out and forces you to make moves you don't select.
After talking to Crystal Moogle from PO, the details behind what's causing the bug are still a mystery, but it seems strongly linked to using old versions of PO. The best thing you can do to avoid it is to make sure to update your client to version 2.0.1. You don't have to use the new battle window, but just update to the latest client version and it should fix your issues. I've had this bug happen to me a grand total of once under the new client, and it might have just been because my opponent was using the old client (not sure how that works, but whatever).
TL;DR: Update PO before playing your matches, dudes.