Cookies are always "Session"

I'm using Intraweb 16.0.4 on Delphi 10.2 (Update 3). In ServerController|CookieOptions I have the following:

CookieNameSuffix: &tempty&t
HttpOnly: false
RunCookieCheck: true
SameSite: ssoLax
Secure: false
SessionCookies: false
UseCookies: true

I create a cookie with this call:

    WebApplication.response.Cookies.AddCookie('Username', xUser, '/', Now + 180);

I create three other cookies in the same manner.

However, upon inspection in the browser, all the cookies are created as session cookies. This is true in Firefox, Chrome and various other browsers.

How do I generate persistent cookies?