I cannot believe you have exactly the same problem I do at the same institution.
I had an excess contribution in 2019 to a Fidelity HSA that I cannot correct as well. I filled out the Fidelity Return of Excess Contribution to form (download from Fidelity) and mailed it. They returned the form to me and included a letter to call them.
I called them today and they said they can only go back to 2021 to remove excess HSA contributions! They said I need to consult a tax specialist. I'm very frustrated. I think Fidelity needs to process this and issue the correct IRS form to me for taxes this year.
