For anyone coming across this thread with the same problem. I downloaded Process Monitor from Microsoft and added a Path filter.
I identified the application which was creating the files. It was actually cache being created by my DAM software. Moved the cache to another m.2 SSD.
My 500GB m.2 Windows drive keeps on getting full due to getting full of temporary files which I then have to manually delete.
Last time I checked there was 193GB of files in C:\Users\username\AppData\Local\Temp.
Is there a way in Windows to identify the application which is creating these files?