Hi Aaron,
please provide your Fix Level, esp. IS_9.8_Core_Fix and SCG_9.8_TPL_Fix, as these contain updates relevant for using SFTP.
Reusing the session key means, that after logging in to the SFTP ServerAlias/UserAlias combination you persist this variable in the pipeline and map it as an input to all subsequent sftp calls like put, get, logout.
Make sure that this value is available inside branches, loops, repeats, sequences etc. if neccessary.
If if the variable seems to be available in the pipeline by design time it might be possible that this is not the case in run time as the scope might have changed which you were not aware of at design time.
Can you share a complete outline of your service?
Regards,
Holger
#webMethods#Integration-Server-and-ESB