No champions or XP - Game breaking bug!

I just went into a ranked TFT match and had a game breaking bug that caused the champion purchasing window to not appear. Without the window it was not possible to buy champions. Upon leaving and re-logging in the window was present but had no champions at all and it wasn't possible to refresh the store or buy XP. Additionally, it was not possible to sell champions. Interestingly it appeared that no experience was gained as it was only ever possible to put in one champion at a time.

Rest assured, I won't be playing TFT again until this bug is fixed.