Thanks for the suggestion, but I've already deleted and re-installed the app. I use the Roku remote to enter username & password. This affects ALL of my Roku streaming stuff. The only thing I have not tried is a factory reset. I haven't done this because it seems to affect all my Roku systems. I am suspicious that there is a bug in the App. I'm curious if others are having a similar difficulty.
You said deleted and reinstalled. I said delete, reboot, and reinstall. Different.
True, it might not make a difference with your situation, but if you didn't reboot after you removed and before you reinstalled, it didn't count. So, let's rule that out before you do a factory reset.