Wells Fargo’s principal regulator has said the bank has a massive backlog of employee human-resources complaints and poor controls around pay, a rebuke that adds to the long list of problems facing the lender’s new chief executive.

The bank has been at pains to demonstrate since the October hiring of Charles Scharf as CEO that it is making progress repairing the regulatory messes that emerged after a 2016 fake-account scandal, which upended Wells Fargo’s reputation as a staid mortgage lender and forced out some of its top executives.