Anonymous plugin's isAnonymous field missing from the cached session

Hello, I have an issue with the anonymous plugin. The problem is when I log in with: await authClient.signIn.anonymous() it works but the issue is that it does not show me the isAnonymous field. I have followed the documentation about infering fields in customSession from other plugins but it does not work. isAnonymous gives me undefined. I am using session caching. After the session cache refreshes then I get the isAnonymous field