Error Connecting to Elasticache Redis Serverless - How to use TextWriter for Details

Id like to use an Elasticache Redis Serverless instance from a Lambda for "aggregating" data as it is ingested (write-thru cache).

StringWriter sw = new StringWriter();
ConfigurationOptions redCfgOptions = new ConfigurationOptions
{
EndPoints =
{
{ envRedisEndPoint, envRedisPort }
},
Ssl = true,
ConnectRetry = 3
}

ConnectionMutliplexer redis = ConnectionMultiplexer.Connect(redCfgOption, sw);
context.Logger.LogInformation("Connected !")

Elasticache Redis is configured and a .Net Lambda is deployed with a StringWriter when trying to connect.
I never get i get the following when it tries

2024-05-03T16:36:45.046Z 9349f934-4fe6-5d45-90dd-a79b5b290b8e fail It was not possible to connect to the redis server(s). Error connecting right now. To allow this multiplexer to continue retrying until it's able to connect, use abortConnect=false in your connection string or AbortOnConnectFail=false; in your code.

So I will try AbortOnConnectFail=false but what I really want first is what am I doing wrong with StringWriter (impl of TextWriter abstract)

The report names StringWriter, ConfigurationOptions, and ConnectionMultiplexer.Connect but no repository files, tests, or implementation entry points. Start by locating the connection diagnostics API and reproducing the Elasticache connection attempt; done means establishing whether the TextWriter usage is incorrect and documenting a confirmed, actionable resolution.