Roth IRA recharacterization after broker transfer - Fidelity said it was easy?

Made $4,078 in Roth IRA contributions at Schwab this year, plus a $13,109 rollover from old Roth 401(k). Income too high for 2025, need to recharacterize regular contributions only (not the rollover).

Fidelity convinced me to transfer everything from Schwab (wanted fractional ETF shares anyway). They said they’d handle the recharacterization easily, but now asking for a letter with NIA calculations. Account was ~$18,458 at transfer with ~$1,271 in gains.

Questions:
1. Anyone done recharacterization after transferring brokers?
2. which broker is required to do this calculation, both say they are not able to.
3. Should I provide my NIA calculation (~$301) or let them calculate?

Need only the $4,078 + earnings moved to Traditional IRA, rollover stays in Roth IRA
Thanks!