.NetCore JwtBearerAuthentication not rejecting expired tokens

I stumbled over the answer here if anyone is interested.
Default value for ClockSkew is 5 minutes.

app.UseJwtBearerAuthentication(new JwtBearerOptions()
{
    AutomaticAuthenticate = true,
    AutomaticChallenge = true,
    TokenValidationParameters = new TokenValidationParameters()
    {
        ValidIssuer = Configuration["Tokens:Issuer"],
        ValidAudience = Configuration["Tokens:Audience"],
        ValidateIssuerSigningKey = true,
        IssuerSigningKey = new Certificate(certPath: Configuration["Tokens:Certificate"], isValid: false).SecurityKey,
        ValidateLifetime = true,
        ValidateIssuer = true,
        ValidateAudience = true,
        ClockSkew = TimeSpan.Zero
    },
});