NEW YORK—FedEx Corp investors approved billionaire Chief Executive Fred Smith’s $54 million pay plan on Monday at the delivery company’s annual meeting, but rebuffed the corporate board’s recommendations on shareholder proposals on lobbying and outsized executive severance packages. Investors approved by more than 50 percent non-binding proposals for more disclosures on the company’s lobbying and for shareholder voting on senior management severance packages that pay out more than roughly three times salary and bonus, known as “golden parachutes.” The investor support is part of a sea change this year as top funds throw more of their weight behind shareholder challenges to companies on environmental, social, and governance (ESG) issues. “It is clear mainstream investors have had enough with FedEx and its exposure to dark money politics,” said Michael Pryce-Jones, senior corporate governance analyst at the International Brotherhood of Teamsters, which sponsored the lobbying proposal. “Partial disclosure only begs the question: …