I'm no tax expert but had an excess to resolve but different situation which led me to Form 5329. From what I've read on this, if you remove the excess for 2020 by the filing deadline you avoid the 6% penalty (not sure about the 10% early withdrawal penalty) - but the earnings are taxable in the year of the contribution and you need to file Form 5329 for 2020 not 2021. Suggest to go over the instructions for Form 5329. If you already filed you may need to file an amended return or may be able to submit Form 5329 separately.
