He went off to visit Emily and never returned. I remember the scene where it was mentioned
In early 2018, Ken Barlow (William Roache) told Sophie Webster (Brooke Vincent) that Emily was back in the country, to look after a sick Freda. Ken told Sophie that they might see Emily back in Weatherfield soon. In April, Mary Taylor (Patti Clare) mentions to Jude and Angie Appleton (Paddy Wallace and Victoria Ekanoye) that Norris has visited Emily.
https://en.wikipedia.org/wiki/Emily_Bishop