Mr. Burris’s case is a continuing headache for JPMorgan in a business line — financial advice and asset management — that has been seen as among the primary sources of growth for it and other big banks. Since the financial crisis, the kind of work that Mr. Burris did, managing money for clients, has been seen as relatively risk-free revenue for the banks.

But his case has been a reminder of how the asset management business can expose the banks to conflicts of interest, especially when they run their own mutual funds. It also shows how hard it can be for the banks to police the far-flung multitudes of brokers and financial advisers they are assembling.

Mr. Burris worked as a financial adviser in Arizona at the JPMorgan Sun City West branch, outside Phoenix, mostly serving retirees in the area. His problems at the firm mounted quickly in 2012.

At the beginning of the year, he received a glowing employee review from the same woman who later wrote up the complaints against him, and he was promoted to work in the elite Chase Private Client division. At the time Mr. Burris had no client complaints on his regulatory records.

But Mr. Burris says he began to push back internally when his supervisors urged him to sell his customers JPMorgan-branded mutual funds in so-called managed accounts. Other JPMorgan brokers complained publicly around the same time about facing similar pressures from their superiors.

It was soon after Mr. Burris began raising these concerns that his supervisors voiced unhappiness with some of his practices as a broker and within a few months he was fired.

Mr. Burris said that he was fired because he refused to sell in-house mutual funds. He questioned the supposed misdeeds that the bank cited for dismissing him. In a few cases, Mr. Burris’s supervisors said he had encouraged a client to make a trade but then marked it down as if the trade had been initiated by the client — suggesting that Mr. Burris was hiding his activity.