I have an existing Roku account that's a few years old. In the last 2 months I added 2 Roku Express to my account with out any issue. Today I tried to add another Express to my account and now it's asking for a credit card, which it has never done for my previous Roku's. Even if I try to add it from inside my account page it ends up asking for a CC. I can't seem to find any way around this. I saw there's a nocc link for signing up new accounts without a CC but doesn't seem to work for existing.
I did a factory reset on my Ultra a week ago, and didn't encounter that when I added it back into my account. However, I didn't actually go into my account previously and remove it, so perhaps it skipped that step. But it still did everything else that a new player would have done, so I really don't know. I just checked my account, and I do have a CC registered with them. However, that card expired 5 years ago and I've never been asked to update it.
If you go in to the older express settings> scroll down to Payment Method, is there one listed?