Last week, WeWork’s parent, the We Company, was forced to postpone a planned initial public offering amid investors’ concerns about the company’s huge losses and the way that it is run.

We’s botched I.P.O. could prove to be one of the biggest flops on Wall Street. Other high-flying start-ups, including Uber and Lyft, were also unprofitable when they went public earlier this year. And long before Uber’s I.P.O., its co-founder was ousted amid a growing number of internal scandals. But there are fundamental questions about WeWork’s core business, which is losing money in relatively good economic times.

WeWork’s board members and investors have not yet approached Mr. Neumann about their concerns, these people said. But Mr. Neumann has indicated that he is not interested in relinquishing any more power. He had already agreed to some corporate governance changes that reduce his control, including the naming of a lead independent director and a reduction in his voting power.

It is unclear how the board could remove Mr. Neumann, who controls the voting power within the company, without his consent. Several investors have floated the idea of threatening Mr. Neumann with legal action, potentially over self-dealing, two of the people said. Some investors want to pursue an investigation of Mr. Neumann’s use of corporate money and well as whether he engaged in drug use on the job. Last week, The Wall Street Journal reported that Mr. Neumann transported marijuana on a private plane over international borders.

Spokesmen for both WeWork and SoftBank declined to comment.

For much of its nine-year history, WeWork was seen as a start-up with seemingly limitless possibilities. It turned the business of co-working — leasing huge amounts of office space and converting it into work areas that it rents out to professionals and companies — into an operation with meteoric growth. It is now the single biggest private tenant in Manhattan.