SoftBank Group continues to suffer fallout from the conspicuous missteps of its venture fund.

Michael Ronen has stepped down from his position as managing partner of U.S. investments at SoftBank Vision Fund, the Financial Times reports. Ronen said in an interview with FT that he had been negotiating the specifics of his departure for weeks after raising issues he had with the fund.

Ronen joined SoftBank in 2017 from Goldman Sachs and has mainly led investments into transportation-based companies like GM's self-driving auto subsidiary Cruise, FT reports.

He may soon be followed out the door by a figure far more central to SoftBank and its real estate investments in particular.

Ron Fisher, one of SoftBank CEO Masayoshi Son's longest-serving executives, is also considering an exit from the company, the FT reports. Fisher was SoftBank's representative on WeWork's board for years and was reportedly Son's primary avatar in directing the startup's growth strategy.

In 2019, two of the Vision Fund's biggest investments encountered major setbacks that cost the fund upward of $5B. Uber's value after its initial public offering in the spring has still not come close to its highest private valuation, and WeWork's IPO didn't even make it to the starting line before the coworking startup's value collapsed.

About half of Vision Fund's equity came from two sources, Saudi Arabia Public Investment Fund and Mubadala Invesment Co., the Arab emirate's sovereign wealth fund. Neither have expressed any interest in Vision Fund 2, which Son announced in July. Though Son touted major early commitments in the second fund from the likes of Apple, Microsoft and the sovereign wealth fund of Kazakhstan, no official investments have been made to date, the FT reports.

Son has promised not to repeat the mistakes of Vision Fund in the sequel, increasing SoftBank's own equity commitment and promising to focus on investments with a clear path to profitability and quicker exits, CNBC reported in October. Global investor confidence in Son remains shaken by what the SoftBank chief himself called "really bad judgment" in his encouragement of WeWork's excesses, the FT reports.