IIS Samesite Cookie working for Lax and Strict but does not work for None - iis

Question

Can someone spot if I'm missing anything else?
Following the direction from https://learn.microsoft.com/en-us/aspnet/samesite/system-web-samesite, this is the IIS web.config I got for Strict:
<system.web>
<anonymousIdentification cookieRequireSSL="true" />
<authentication>
<forms cookieSameSite="Strict" requireSSL="true" />
</authentication>
<sessionState cookieSameSite="Strict" />
<httpCookies sameSite="Strict" requireSSL="true" />
<roleManager cookieRequireSSL="true" />
<compilation targetFramework="4.7">
...
</compilation>
...
<httpRuntime targetFramework="4.7"/>
</system.web>
And the result (Sorry, I couldn't embed image directly. Got error "couldn't reach Imgur"):
samesite="Strict" image
For SameSite="None", I simply change all the "Strict" to "None":
<system.web>
<anonymousIdentification cookieRequireSSL="true" />
<authentication>
<forms cookieSameSite="None" requireSSL="true" />
</authentication>
<sessionState cookieSameSite="None" />
<httpCookies sameSite="None" requireSSL="true" />
<roleManager cookieRequireSSL="true" />
<compilation targetFramework="4.7">
...
</compilation>
...
<httpRuntime targetFramework="4.7"/>
</system.web>
But it is not being added to the cookies:
samesite="None" image
Thanks in advance. Appreciate your help.

Answer 1

There was a comment in another thread that I was thinking of trying as the last resort due to the trouble of installing any software on the machine. It doesn't exactly match my scenario as it didn't work even when he was using "Strict". However, it does fix my problem after installing URL Rewrite.
I tried with <httpCookies sameSite="Strict" /> in .Net 4.7.2 but it did not work for the Asp.Net Identity cookie. This rewrite rule did. – Augusto Barreto Nov 22 '18 at 22:30
#AugustoBarreto Asp.Net Identity ignore the .config settings. Solution is to implement your own Cookie Handler. Derive from System.IdentityModel.Services.CookieHandler and implement WriteInternal method. – Saftpresse99 Mar 18 '19 at 12:18
Thanks, Augusto!