Hi Dusk,
why are you creating several subVIs which contain the very same content? (Atleast it seems so from a quick glance at them.)
They are calling some DLL functions: either the DLL supports multithreading, then you should set your VI reentrant - or they don't support multithreading, then you should call them one after the other…
Anyway the problem is in your main VI: Learn to use autoindexing and learn, how to handle arrays!
Both are basic LabVIEW concepts and you should know about them, before handling DLL calls…
Best regards,
GerdW
using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019