Bit more detail here.....Seems when the scheduling was being done in the 48 hrs between the draw and confirmation no one in the EFL or Everton bothered to reach out and remind UEFA our fixture was already scheduled and our lovely neighbours could have played on the Tuesday quite easily especially as they play the Friday night before in the league....

https://www.bbc.co.uk/sport/football/articles/cx2zq97w28eo