It was in the final 3 minutes of Q1 and several drivers, especially Perez, stood still too long in the pitlane exit waiting for the green and the tires lost temperature. It really disadvantaged several drivers
Perez just failed to do a good time. Although he kinda got shafted by being the first one out after the red flag on used tires, since he was drying the track for everyone behind him.
Perez was overly cautious on his final lap. He really doesn't look comfortable in the wet as we've already seen this season. Took too few risks and just ended up slow.
Was a red flag 3 minutes before the end. So everyone had a single chance to set their top time. Especially with the track drying. Perez just didn’t set a good enough time. Maybe if he waited a little bit longer to set a time the track would‘be been a bit faster. It was improving a lot.
Checo absolutely should have been able to get through. The team didn't help him by putting him out at the front after the red flag, but there's not really any excuse for not making it this time.