Allen Proithis, the high profile North American head of Internet of Things (IoT) network firm Sigfox, left the company because of management differences with Sigfox’s leadership.

Proithis’ departure, which was first reported by Light Reading, comes amid reported turmoil at the French-based firm. Thomas Schmidt, the company’s spectrum manager, also has left the company.

In an interview with SDxCentral, Proithis said that almost all of the company’s original management team has departed and has not been replaced. However, he added that he is still a big believer in Sigfox’s technology and thinks there is a lot of potential for success in IoT. Currently, Proithis is working on some consulting projects, but he hopes to stay in the IoT field.

For its part, Sigfox told FierceWireless in a statement that the company parted ways with Proithis as part of a strategic decision to take Sigfox to the next phase of its evolution in the U.S. market. Sigfox also responded to SDxCentral saying that Christian Olivier has been named North America Regional Director for the company and he will act as the lead for that region in the interim.

The company also has hired Franck Siegel as its chief delivery officer. Siegel will report to Sigfox CEO Ludovic Le Moan and will oversee a number of departments including the company’s marketing, engineering, operations, IT, security, program management office, and human resources.

Siegel is a former officer in the French Navy and has worked for BT, Verizon, and Dimension Data.

Sigfox made headlines in November 2016 when it closed on $159 million in Series E funding from new investors that included Salesforce, Total, Henri Seydoux, Alto Invest, Swen CP, and Tamer Group as well as existing shareholders including Bpifrance, Elliott, Intel Capital, Air Liquide, Idinvest Partners, and IXO.

The company uses a narrowband technology coupled with a standard radio transmission method called binary phase-shift keying (BPSK). At the time, it said it was going to use the funding to expand its network to 60 countries by 2018 and break even financially.

Currently Sigfox’s network is in 43 countries and has more than 2.5 million active devices. The company said in a statement that it plans to expand its reach to 60 countries this year and connect up to 10 million devices.

But Sigfox isn’t the only IoT company tweaking its leadership and/or business model. Low-power wide area (LoRa) networking company Senet has a new CEO and a new business model. The company early on focused on building a LoRa network but is now using its expertise to help other companies build IoT businesses.

In addition, IoT company Ingenu, which uses a proprietary technology called random phase multiple access (RPMA), has named Babak Razi, managing partner of Third Wave Ventures as its interim CEO to replace former CEO John Horn. The company is searching for a permanent replacement and is undergoing a realignment of its business.

Update:  This article was updated to include that Christian Olivier has been named North America Regional Director for Sigfox.