Redis Sentinel: The ConnectionMultiplexer is not a Sentinel connection. Detected as: Standalone error

Our project is a .NET 8 API project, and we are using StackExchange.Redis version 2.8.0 as a caching mechanism. However, we are randomly encountering an error that shows "Sentinel: The ConnectionMultiplexer is not a Sentinel connection. Detected as: Standalone," and sometimes we don't receive this error. I haven't been able to identify the cause of this issue. What steps should I follow to resolve this error? I am sharing our codes

 var redisConfigurationOptions = new ConfigurationOptions()
                {
                    EndPoints = { { redisConfiguration.SentinelUrl!, redisConfiguration.Port } },
                    Password = redisConfiguration.Password,
                    ServiceName = redisConfiguration.ServiceName,
                    AbortOnConnectFail = redisConfiguration.AbortOnConnectFail, 
                    ConnectRetry = redisConfiguration.ConnectRetry, 
                    ConnectTimeout = redisConfiguration.ConnectTimeout, 
                    ReconnectRetryPolicy = new LinearRetry(redisConfiguration.ReconnectRetry) 
                
                };
var redisClient = ConnectionMultiplexer.Connect(redisConfigurationOptions)```

And redisConfiguration.SentinelUrl = redissentineltest.ourproject.com redisConfiguration.Port = 26397

Start with the ConfigurationOptions and ConnectionMultiplexer.Connect call shown in the report, checking the SentinelUrl, port 26397, password, and ServiceName against the Redis Sentinel setup. Reproduce the intermittent failure and compare the connection mode reported in the error; done means the client consistently recognizes the endpoint as Sentinel without the Standalone error.