Bug a) has been noticed by several users:
https://ttlc.intuit.com/community/taxes/discussion/tt-2025-desktop-carryover-worksheet-bug/00/371090...
Regarding bug b), for now an override might be needed.
Early releases of TurboTax are notoriously buggy. I would not recommend beginning your actual tax return for any tax year until the following January when TurboTax is somewhat more stable. I would treat any tax return begun prior to that as a test tax return.
