I reviewed your file. Sorry for the delay.
First, the penalty you are seeing in the summary isn't because of your contributions, there is no penalty calculated on Form 5329. You have a penalty in your summary because you haven't had enough taxes withheld in 2021. Please see Topic No. 306 Penalty for Underpayment of Estimated Tax for more details.
Second, it seems as if you had pre-tax amounts in your traditional/SEP/SIMPLE IRAs. For a backdoor Roth to work correctly your traditional/SEP/SIMPLE IRAs need to be empty or at least only have after-tax funds in them. Otherwise, each distribution/conversion will have a taxable and nontaxable part because of the pro-rata rule.
TurboTax used the IRS Worksheet 1-1. Figuring the Taxable Part of Your IRA Distribution to calculate the nontaxable part. And since you seem to have pre-tax funds left in your traditional/SEP/SIMPLE IRAs only a small amount of the conversion will be tax-free. The rest of the basis is carried forward on line 14 of Form 8606 for future distributions/conversions.
@omkarprabhu
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