Porro being all over the place defensively seems to be the consensus here, but at this point I'm inclined to blame our next-man-up, gung ho pressing for most of the individual errors. Because even our defensively more astute players such as Danso and Spence are not immune to ending up in weird spots on the pitch while defending. The former was halfway into City's half in the buildup of their goal for example, while the latter was nowhere to be found in the first minute against Ipswich when they were about to score from his side.
Son is the initial domino that falls here, he leaves the left side open by being too ambitious with his effort. This'll be relevant shortly
Bergvall is the next man up, he rotates to the left to pick up Son's assignment. Kulusevski follows Bergvall to possibly provide cover for him. Udogie does likewise to pick up the next pass, which drags Bentancur away from the centre towards the left. But notice how this opens the centre of the pitch. Ipswich player right next to the ref is open already. He can potentially be the one that'll allow them to carry the ball forward if/when they beat this press.
There's already a simple pass to the aforementioned player here, and there's nobody around him that can potentially stop him from carrying the ball forward. Player on the ball misses this passing opportunity by the way.
There's the second opportunity for the said pass, and the player on the ball this time takes it.
As can be expected, the receiver has no problem getting the ball and bursting forward. There's nobody in the close vicinity that can cause him any sort of problem, Johnson's insignificant last second attempt aside.
Spence is the guy inside the centre circle, despite playing RB. Normally you could blame him of being way out of position, but he's just the next man up in this scenario. He's all the way up there because the entire midfield trio of Bentancur-Bergvall-Kulusevski is behind the play, which is related to other dominoes falling earlier.
This is straightforward stuff from now on. A simple pass to a runner, who'll challenge Gray at 1v1 and have a crack at it.
My takeaway is this: Our pressing is extremely naive and puts unrealistic expectations on players. They're almost expected to man mark full length of the pitch at all times, without anybody missing any assignment. No picking your spots, no insurance, nothing. So even a minor hiccup in the form of getting beaten off the dribble or missing an interception creates a domino effect where more and more players are dragged out of position until almost everybody ends up behind the play and tries to scramble back in desperation.
This doesn't mean that this team is full of defensive stalwarts. But I think our almost nonexistent team shape is the main issue here.