Cloudflare DDos protection : JS challenge

Hi, I am making my browser.
But I have some problem about cloudflare DDos protection,
I am stuck at just a moment thingy by cloudflare while accessing some sites using my browser.
(It is OK using chrome on same network)
After debugging I found that cf-chl-rc-ni was not passed to my browser. As far as I know the client(browser) sends cf_seq_XXX to server and in response the server sends cf_chl_rc_ni to the browser.
Why doesn’t server send cf_chl_rc_ni?
Please help me!!
Thank you

Do you have any antivirus type plugins? Have you tried incognito mode?

Thank you for response.
But, my browser does not have antivirus type plugins and incognito mode.
I made my browser based on chrome ‘content shell’
Is there another thing I will check?
Thank you

@MoreHelp

What browser+ browser version are you using?