First, there's nothing wrong with Matthew or John. But the specific statement, that it was the day the passover was killed, is only made by Luke and Mark. Matthew gives half of the statement in saying that it was the first of unleavened.
It appears that you are saying that Peter and John went and prepared the passover after sunset on the beginning of the 14th, which would be before all leaven had been removed. Three gospels expressly state that the two disciples went and made ready the passover. If that is what you are saying, you are gravely mistaken. If you are saying that they didn't go and make ready the passover, then you are ignoring the direct statements of three gospels.
As is so often the case, you are simply mistaken. I have been studying this topic for more than twenty years. I very much know what I'm talking about. And I haven't been applying interpretation. I'm just standing on the direct statements of scripture. On the first day of unleavened bread, when they killed the passover, two disciples were sent to make ready the passover. And they did as instructed and made ready the passover. Anything you say that contradicts that is on you. You are just wrong.
Well, "Yeshua" said that he would keep the passover at the good man's house. By your interpretation, he lied. Paul never said what day it happened. He only mentioned one of the many symbolic significances of Christ's death, and the apostles say he ate the passover.