Bug: Caching issues when following initial instruction #20

Based on the example provided I've tried to install library with the following steps:

1. Added the Joystick client in the ConfigureServices:

// Joystick
builder.Services.AddJoystickClient();
builder.Services.AddOptions<JoystickClientConfig>()
    .Bind(builder.Configuration.GetSection("JoystickConfig"));

And added appropriate configuration to appsettings.json:

{
  "JoystickConfig": {
      "ApiKey": "...",
      "CacheOptions": {
          "CacheExpirationSeconds": 600
      }
  }
}

2. Added client code for the controller (for test purposes);

        var fullContent = await client.GetFullContentAsync(configName);
        var fullContent2 = await client.GetFullContentAsync(configName);
        var fullContent3 = await client.GetFullContentAsync(configName);
        var fullContent4 = await client.GetFullContentAsync(configName);
        var fullContent5 = await client.GetFullContentAsync(configName);

3. Triggered new API endpoint with Postman perf test.

Every additional copy-pasted line drastically increases the response time of the specified API call.

Graph of response times over time for version where there's 1 call to Joystick library to get the same config:

Graph of response times over time for version where there're 5 calls to Joystick:

Sounds like the problem is related to cache.