A Microsoft spokesperson told Business Insider that the company had "recently became aware of a report that claims InPrivate tabs are not working as designed and we are committed to resolving this as quickly as possible."
The flaw is damaging for Edge, which has had a rocky start after shipping without extensions — such as AdBlock or Hola, the VPN service — or other standard features in Chrome or Safari. Microsoft has said that extensions are coming in summer 2016.
According to The Verge, other browsers, including Chrome, Safari, and Firefox, have also had this issue, showing that private browsing mode is not meant to deflect an investigation of the hard drive.
Edge is currently used by around 3% of the total desktop browser market, according to Netmarketshare. Internet Explorer, which Edge replaces, has a combined share of 45%. Windows 10 comes with Edge installed as the default browser.