u/Intelligent_Ad_5162

I was wondering if this was a potential plot hole: at the start of shinobu time the darkness appears as a result of hachikuji walking home with him and as a result of her not doing her "job" as the lost snail right? But wasnt the whole reasoning behind this that she was picking up her bag that she left at araragis house so technically she already didnt fufill her role as the lost snail by them entering his house together before this? Why didnt the darkness appear then?

Sorry if its a dumb question was just wanting some possible clarification