[Escaped characters, Unicode escapes] Working on 6.3.* is different with 6.1.*

Sending a POST request which includes Escaped characters, Unicode escapes in request body, here is the result at 2 versions:

  • At 6.1.*: Treat escaped letters as normal string.(E.g.: Sent \n is just a string \n, no new line inserted)
  • At 6.3.*: Treat escaped letters in the body as their meaning. (E.g: \n as a new line, \u0026 as a & letter…)

Is this a normal work result?
Expected that the behavior on 6.3.* should be the same as 6.1.*.