Control Container causes error "loop in tool connections" where regular container works ok

[compunut]

Can anyone explain why this configuration is considered a LOOP by the Control Container - yet the process runs fine within a regular Container?
I intended to make two Control Containers of a similar nature and chain them in order, simply because they write to the same audit file, and thought to use them rather than an arbitrary Block Until Done scenario.

[jordanmount6]

This is a previous related topic where the author said there was a missing connection somewhere. 

https://community.alteryx.com/t5/Alteryx-Designer-Desktop-Discussions/Loop-in-tool-connections-while...

[compunut]

If AMP engine is turned off as suggested in other thread then

Error: Control Container (51): Control Containers are not supported in the original engine, enable AMP Engine to use this functionality.

[compunut]

And I don't believe there are any "missing connections" as mentioned in other thread as a working flow was simply wrapped in a Control Container...

(unless the Control Container REQUIRES some input/output connection??)