Is the CP21B refund taxable for Oregon State in 2022?

Yes, the question asks if you received an additional refund. 

"When would I report an additional federal income tax refund from a prior year tax return?

You must report the amount of federal tax refund from which you received a tax benefit. The tax benefit is the amount of federal tax you deducted as a federal tax subtraction in a prior year Oregon return but later received as a refund due to an amended or audited federal return. If your federal tax subtraction on your prior year Oregon return would not have changed because of the additional federal tax refund, then you would not need to report the additional federal tax refund on your current year Oregon return."