Balde had the runner covered at the 2nd goal. Goal was a total gift by Tek. For the other 3 yes, there were defensive issues, but not due to the high line this time. Kounde, Araujo, Cubarsi simply covered their area too slowly.
First goal. Switch to the blind side, Kounde joggs and is lazy in covering the cross, Benfica guy crosses unbothered, Araujo is only concerned with his man, ball goes to the other striker who is marked poorly by Cubarsi.
2nd goal is simple.
3rd goal is a dangerous action by Benfica due to Araujo's poor ball-playing ability. Doesn't know how to positions himself to receive a pass, is flatfooted often. There is a turnover in a dangerous position and Benfica builds a nice attack through a string of quick passes that lead to the stupid pen caused by Tek. Goal, despite errors preceding it from our defense, is preventable if Tek stays put.
4th goal also starts from Kounde half-assing it in covering his wing and blocking the cross. Then Araujo does his thing by commiting instead of informing himself first. Maybe Kounde thought he is Dani Alves after he scored some goals lately. Well, he isn't, so he'd better pay attention in defense, because that's supposed to be his thing.
Neither goal is directly due to the high line. Most are due to individual errors. Of course, if you don't play a high line, more players can participate in defense and such errors can be stopped in time. With a high-line, you fuck-up, you are toast as all the players are occupying advanced positions. But then, if you drop your positions in a lower-block, you get more defensive solidity and compactness, but lose the ability to create as many chances as we do.
The only systemic problems that have been exploited by Benfica were some bad turnovers by Araujo, Casado, Gavi, and Yamal. The first three gave the ball away when they shouldn't have, and Yamal was trying some unnecessary fancy tricks, reminding me of the worst moments of Neymar.