It didn't make me surprised to see Tottenham and Manchester United both failing to win yesterday.

Because their look in the league phase was just deceiving. It wasn't linking with their performances.
Shortly after this phase ended we saw it clearly. AZ could have won even with a bigger goal difference. Tottenham were terrible. I don't think they will make a comeback with this spiritless game. As for Manchester United, it wasn't an easy game for them from the start. The same for Real Sociedad also. Honestly they are both boring clubs this season. I don't care which one gets past this round. I think we could watch extra time and even penalty shoot-outs in the rematch. I expect a low-scoring game in regular time.
I was surprised Manchester United managed to produce such a brilliant performance in Spain. However they let their guard down are in the game, conceding a goal and ultimately settling for a draw. While it was a decent result, United could have secured a win if they had played better. It would be interesting to see if Manchester United can qualify for the next phase of the competition. As for Tottenham, their performance was disappointing. They failed to capitalize on their opponent's weakness and lacked the sharpness needed to secure a victory.