Thank you very much!
You are indeed right that renaming = new file, even though it annoys me not being able to discern between modified name and actual new file. Still for now it is workable for me.
Thank you for your help and time - it lets me progress my general code now.
I do hope though that this becomes much better, because I find it so unbelievable that a language as Julia, which is good at so many things, actually struggles to properly close down subtasks and perform IO operations - thankfully you gave me the quick workaround, which is why I marked your answer as solution.
Kind regards