Can't prevent Cookie reading in privacy window, even after deleting the cookies

Hello, I’m regular user of the browser and today I was surprised that Brave private window was unable to protect my privacy by allowing reading of cookie, thus automatically logging in me into site. The issue was able replicate with sites like http://www.whatarecookies.com/cookietest.asp.

Step to reproduce:
Variant 1:

  1. Open http://www.whatarecookies.com/cookietest.asp in any window (private or not)
  2. Open in new Incognito or Private window, the message for your last visit should be displayed.

Variant 2:

  1. Open http://www.whatarecookies.com/cookietest.asp in Private mode
  2. Delete cookies/history (without closing the window)
  3. Test in another new Private window, your last visit time should be displayed.

This issue is not present in Firefox private browsing, even without deleting cookies (doesn’t apply for multiple private windows).

If Brave wants to make browsing private, it should not only prevent writing of data in Private mode, but also prevent reading or cookies by default, to be honest I don’t know what to change to make it stop reading the cookies, any ideas?