There are instances when these settings get corrupted, alter on their own, or are affected by another file (not necessarily a virus).

After a significant amount of time has passed, it is not unusual for the settings to be adjusted in some way. In some cases, the problem might be caused by something as simple as a corrupted setting or file. However, you should be aware that your browsing activity will still be visible to websites you visit, including the ads and resources used on those sites, your employer, school, or whoever runs the network you’re using, and your Internet Service Provider (ISP). The Incognito mode can come in handy in a variety of ways, as it won’t save the following info: browsing history, cookies and site data, information entered in forms, and more. However, some users reported they had no Incognito mode in Chrome. In the case of Chrome, if you don’t want it to remember your activity, you can use it privately in Incognito mode. Plenty of browsers have implemented a browsing method that is advertised as being far more secure. Home › Browsers › Chrome › Why can't I go incognito

Open google chrome in safe mode