hi @Vlogbox sorry for your troubles ,
but .... lately Roku implemented a lot of changes , some of them mandatory from the first of April , like adding ads-txt if you have monetization on your channel , new testing .... so on ...
maybe that could be a reason , but Roku Dev support is the best to give you info about your channels in particular.
i know it is not a lot of help but usually when Roku takes a channel down ( like put it private) the channel doesn't comply with something they require
Building a TV Channel can be easy … if you have a right tools ===>> https://tv-channel.info/