Answer
Check the user's Companies & Sites grant under Solution Manager > Security > Users — access needs to be explicitly checked/granted per company there, and having a working session in a company isn't the same as having full data access granted for that company. Separately, also check whether an additional Business Role grant is needed for company-level General Ledger data specifically, an Authorize Class found under Business Roles > General Ledger in the same user record, since some GL-specific reporting screens like Balance Analysis can require both the direct company access grant AND a relevant authorize-class-based Business Role before they'll return any data for a given company.