As I understand flow logic, any action lacking a previous link will execute simultaneously when the process or flow starts. Since the "Check Traffic Status" loop has no pre-requisite actions, it will execute at the same time as the "Arrays - Get Array Length" action since it reads them both as the first thing to execute in the "Select first server" loop.
When Jacky replied earlier, he was referencing the gray line connecting the "FTX Nac" flow with the action "Lx script". This line will still determine an order to process actions and flow (process the Lx script action after the FTX Nac flow) but it will execute regardless of the result of the previous actions even if that is result is cancelled.