Real Madrid didn't lose, they just failed to win a match they should have won. However I have to admit that Sevilla played well in that match even though they deserved to lose points at home if not for two disallowed goals, but that is another part that should not be the reason why Real Madrid didn't win.
Sevilla is certainly very confident of performing well at home, and this is proof that they are really able to get into good form after sacking their old coach. Playing a draw against Real Madrid is the same as winning the match, but this draw has certainly harmed Real Madrid, who are in fact the favorites. Sevilla didn't score any goals apart from Alaba's own goal, but they fired 17 shots, 7 of which were on target.
Apart from everything you said, I think the draw that Real Madrid achieved in this match was quite disappointing because they should have won but Real Madrid's performance was really disappointing.
Even though this match was played at Sevilla's home ground, the quality of the Real Madrid team was far above Sevilla and also the Sevilla team had just changed coaches and their performance was quite bad in the last few matches so the results achieved by Real Madrid were really not worthy.
Real Madrid have to improve a lot if they want to win the title this season, especially their front line which needs to be improved again. In this match, Real Madrid's front line was seen to be less sharp and unable to take advantage of opportunities/create chances.