Docker Application loses connection to external service after 5 minutes

Assume this Scenario: A container with ubuntu and an application A connect to an external Service B on port 11111. A communicates, then there is a pause of 7 minutes and then A communicates again.

If I run this Image on a Linux Host (openSuSE) all is fine. - If I run the same Image on a Windows Host with Docker Desktop stable the second Connection doesn’t work: the Connection is already closed.
So I wiresharked both variants in the container and near the external Service:
The Linux-Architecture records only the normal payload.
The Windows-Architecture records the normal payload in the container. But near the external Service it records every second a keepalive from the Windows host to the Service. After 330 keepalives without other communication the Windows host Closes the Connection (FIN/ACK), then the Service Closes the Connection too (of Course). Only the second FIN/ACK (from the Service) reaches the application in the container.

My Questions:
Which Software sends These unnecessary KeepAlives? Docker Desktop or Windows? And what can I do to get the “normal” timeout of 7200 seconds or to Prevent this Software from Closing my Connections?

Thanks in Advance
< F >