BIG-IP : device-side timeout applied to iControl operations ?

F5 BIG-IP LTM VE v11.4.0 on ESXi

The iControl API classes accept a timeout parameter - which to be safe I set to 3600000 ms = 1 hr ( how to set to infinite ? )

However calls to

LocalLB.DataGroupFile.set_file_path()

API ( that when successful complete in under 10 mins ) sometimes return this error :

The underlying connection was closed: An unexpected error occurred on a send.

Is it possible that BIG-IP is applying its own internal timeout to iControl requests ?

If so, how to configure my BIG-IP device's internal timeout ?