A thick client fails to start if being used inside of a serverless function such as AWS Lamda or Azure Functions. Cloud providers prohibit opening network ports to accept connections on the function's end. In short, the function can only connect to a remote address.
To reproduce, you can follow this tutorial and swap the thin client (used in the tutorial) with the thick one: https://www.gridgain.com/docs/tutorials/serverless/azure_functions_tutorial
The thick client needs to support a mode when the communication SPI doesn't create a server socket if the client is used for serverless computing. This improvement looks like an extra task of this initiative: https://issues.apache.org/jira/browse/IGNITE-12438