California taxes all California source income. Period. There isn't an exception to this.
Oregon taxes all the income you earn as a resident. But if you file your resident return in Oregon and they tax your RSUs then you are entitled to a credit for taxes paid on that money on your California non-resident return. Meaning that California can still tax anything that has already been taxed by Oregon, but they are only entitled to have you pay the tax if the California tax rate is higher than Oregon's (which it probably is). So, the portion that you're paying to California that they are keeping is probably money that they are entitled to due to their tax rate.
Making a free loan to California is the only way to get the refund from California that you're entitled to. On the upside, this is the only time you'll have to deal with this situation.
@blatsnorf
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
