The Days of Unleavened Bread do occur after Passover, but right after, and they are associated with Passover, forming part of the same festal season.
The context wasn’t Passover. The feast was stated in the scripture
“Acts 12:3 ...(Then were the days of unleavened bread.)
The parenthetical stresses a necessary factual understanding that Passover was over and the time was the feast of unleavened bread.
It's "pascha", the same word translated as "Passover" elsewhere in the KJV. There is no justification evident in the text to translate it as anything other than "Passover".
The context is specified as during...the Days of Unleavened Bread...after the Passover.
On Easter the celebration of the resurrection of our passover lamb, Jesus Christ of Nazareth.
What you and the other KJV-onlyists need to do is come up with some first-century evidence that Christians in the earliest decade of the church celebrated "Easter" as distinct from "Passover" and then come up with textual evidence that justifies the use of the term instead of "Passover". So far, there has been nothing approaching either.
The context provided by scripture is precise, and precisely what is needful to determine that it was not Passover, nor the feast of Unleavened Bread that Herod referred to, for Passover was over, it was Easter that Herod wanted to use against the followers of the risen Christ Jesus.
And Herod was judged for his evil intention. Herod was an antichrist. He wanted to rule over Israel. But he was eaten of worms as he sat lusting to be called God.
Herod should’ve taken heed of Psalms 2...
12 Kiss the Son, lest he be angry, and ye perish from the way, when his wrath is kindled but a little. Blessed are all they that put their trust in him.