AdGuard Stealth Mode-third party cookies

[dnmTX]

This could be a bug or just me imagining(if it's the latter,apologies).It's about blocking(destroying) the third-party cookies.In my Chromium browser they are set to be blocked and naturally when they got blocked you see a little icon on the address bar indicating it.

Like this one:

In AdGuard's stealth mode they're set to be destroyed immediately:

The thing is that i still see the little icon in the address bar showing up,sometime after small delay,sometime right a way and considering the fact that AdGuard should intercept all the traffic before the browser the third-party cookies should be destroyed by it not blocked by the browser.
I've been observing this for a while now before deciding to open a issue here so unless i'm wrong and there is no explanation on why i thing it should be looked at.Thank you.

Your environment

AdGuard 6.3.1399.4073 (TDI filter IN USE)
Slimjet 20.0.2.0 (based on Chromium 68.0.3440.75) (Official Build) (64-bit)
Windows 10, v.1607, build 14393.2457

P.S. It's worth mentioning that when try reproducing the issue it's probably a good idea to have
Avast AV(free) installed also as all my problems so far are somehow related to it(see #2310).

[ameshkov]

This might be caused by the fact that AG removes cookies by modifying/adding a Set-Cookie header with a zero expiration timeout, which Chrome might anyway consider a third-party cookie (despite zero lifetime). But we'd better check it.

Moving to CoreLibs.

[ameshkov]

Issue moved to AdguardTeam/CoreLibs #479 via ZenHub