Fail to access API when using IdentityServer 4 on a MAC - asp.net-core

Question

I have 2 ASP.NET Core 2.1 applications (Auth and API) using Identity Server 4.
On API application Startup I have the following:
services
.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddIdentityServerAuthentication(x =>
x.ApiName = "api";
x.Authority = "https://localhost:5005";
x.RequireHttpsMetadata = false;
});
On Auth application Startup I have the following configuration:
services
.AddIdentityServer()
.AddDeveloperSigningCredential()
.AddInMemoryIdentityResources(Config.GetIdentityResources())
.AddInMemoryApiResources(Config.GetApiResources())
.AddInMemoryClients(Config.GetClients())
.AddTestUsers(Config.GetTestUsers());
Where Config class is the following:
public class Config {
public static List<ApiResource> GetApiResources() {
return new List<ApiResource> {
new ApiResource("api", "API Resource")
};
}
public static List<IdentityResource> GetIdentityResources() {
return new List<IdentityResource> {
new IdentityResources.OpenId(),
new IdentityResources.Profile()
};
}
public static List<Client> GetClients() {
return new List<Client> {
new Client {
ClientId = "app",
ClientName = "APP Client",
ClientSecrets = { new Secret("pass".Sha256()) },
AllowedGrantTypes = GrantTypes.ClientCredentials,
AllowedScopes = {
"api"
}
}
}
public static List<TestUser> GetTestUsers() {
return new List<TestUser> {
new TestUser {
SubjectId = "1",
Username = "john",
Password = "john",
Claims = new List<Claim> { new Claim("name", "John") } },
};
}
}
With Postman I am able to access .well-known/openid-configuration and create an Access Token.
However, when I call the API I get the following error:
Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerHandler[3]
Exception occurred while processing message.
System.InvalidOperationException: IDX20803: Unable to obtain configuration from: '[PII is hidden by default.
Set the 'ShowPII' flag in IdentityModelEventSource.cs to true to reveal it.]'. ---> System.IO.IOException: IDX20804: Unable to retrieve document from: '[PII is hidden by default.
Set the 'ShowPII' flag in IdentityModelEventSource.cs to true to reveal it.]'. ---> System.Net.Http.HttpRequestException:
The SSL connection could not be established, see inner exception. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
I ran dotnet dev-certs https --trust; and the localhost certificate appears on Mac Keychain.
Important
On a Windows computer the code I posted works fine.
I am able to access .well-known/openid-configuration and the API endpoint.
What am I missing?