I ended my turn with 8 cards but did not have to discard. This happened in 2 consecutive turns. As I wanted to take screenshots in the 3rd turn, I had to discard as usual. Hence, no screenshots.
The bug may be caused due to me playing SoB while he had Sancts out. This obviously was in the turn before.
Detailed course of events:
He had Sacts out.
My turn: I have 8 cards, play SoB, end my turn.
His turn: Nothing special.
My turn: Draw my eighth card, play SoB, end turn.
His turn: Nothing special.
My turn: Draw my eighth card, end turn, do not discard. WTF...
His turn: Nothing special.
My turn: Do not draw a card, end turn, do not discard. WTF once more...
His turn: Nothing special.
My turn: Do not draw a card, take screenshot, end turn, do discard.
Rest: Business as usual (lose).