For example, https://rviscomi.github.io/capo.js/user/demo/?url=https%3A%2F%2Frviscomi.dev%2F:

The origin trial is not invalid, but because it's being validated on rviscomi.github.io, capo.js incorrectly assumes that's the actual 1P origin, rather than the page being tested, rviscomi.dev in this case.

To fix, capo.js needs to explicitly take the test origin into consideration while running the validation.