Integration not working correctly only in Sub process

we are running Gmail Poller's Connected System in Integration.

This Integration returns a list of Gmail Email Id's.

The TEST REQUEST in the Integation object succeeds and successfully returns a list of Gmail Email Id's.

Running this Integration in a process model also successfully returns a list of movement id's.

However, when this process model is executed as a sub-process, this Integration object does not return a list of ids and returns one empty item.

This sub-process model does not need to and does not reference values from the parent process, as it works as expected normally when executed independently.

Nevertheless, it is not clear why this Integartion node returns an unexpected value only when it runs as a child process.

Can you tell me where I should check?