Is there a breach of fiduciary duty in calculating disability benefits under a pre-set formula?

Acosta v. Brain , 910 F.3d 502, 518 (9th Cir. 2018) (writing that although the threshold question is whether an employer is wearing his "fiduciary hat," the court lacked "basic information such as whether [the defendant] was a named or functional fiduciary"). Nor has our circuit decided whether calculating benefit amounts pursuant to a pre-set formula is a fiduciary function, such that failing to exercise due care in the course of the calculation is a breach of fiduciary duty.