azure-sdk-for-net: ManagedIdentityCredential token cache not working?

I recently upgraded Azure.Identity to version 1.8.2, hoping I can get rid of my token caching implementation and rely on the internal caching. however, from looking at Application Insights logs, it looks like there is no caching going on, and a token is acquired before every access to the database. Here is a screenshot for example. I highlighted requests for a token and the corresponding database calls.

I am using a ChainedTokenCredential like this:

        private static TokenCredential GetCredential()
        {
            return new ChainedTokenCredential(
                new ManagedIdentityCredential(),
                new VisualStudioCredential(),
                new EnvironmentCredential()
            );
        }

and then get a token like this:

        public SqlConnection GetConnection()
        {
            SqlConnection conn = new SqlConnection(Config.ConnectionString);
            if (!Config.IsDevEnvironment)  //in dev we use an on-prem db
            {
                TokenCredential credential = GetCredential();
                
                AccessToken token = credential.GetToken(new TokenRequestContext(new[] { "https://database.windows.net/.default" }), CancellationToken.None);
                
                conn.AccessToken = token.Token;
            }
            return conn;
        }

Am I doing something wrong?