Senthil, thanks for responding. I was able to figure it out, what it was is within the flow it starts by receiving a IDOC from a SAP system, what I found was that the $TID value is being set so when calling the FM from within my flow it would not work as a $tid was already present, I imagine this caused an error but sadly it was never reported. I dropped the value before performing the outboundMap and all is good.
Hope this helps someone in the future.
Regards,
#webMethods#Integration-Server-and-ESB#Adapters-and-E-Standards