Hi Nick,
Migrating a project to higher version is not that straight forward. So not everything would work as it is, you will have to modify stuffs a bit. I remember reading somewhere that pipeline character is not readily supported in all action blocks as it has other meaning too.
I would suggest map your input as stringreplace(string, searchText, replacetext) and then provide delimiter as "replacetext". It would work.
Best Regards,
Swaroop