Not sure if it’s the Roku app or Redbox app but why can’t I see my wishlist on my Roku device?

It's Redbox's app. They create a version to run on the Roku operating system, supply it to Roku, and maintain it. Any features, or lack thereof, are up to them. Roku just supplies the platform on which it runs.

Redbox Help Center: https://help.redbox.com/contact/

I KNOW! It’s so annoying. When I want to watch something from my wish list I have to open Redbox on my iPad, pull up my wish list then search it on Roku’s Redbox app. Just so annoying. But it’s a workaround. Why don’t we also email Redbox about it? I will today. They’ve GOT to know how outrageous this is. 

This is the email for Redbox customer support. Just emailed them per their website. 

customerservice@redbox.com

https://help.redbox.com/contact/