How to deal with a sudden and unexpected ghosting?

i've known this girl off and on for 2 years , sometimes things between us are better than other times. things started out a bit off at the start of this summer but then they got fairly good and we had some good nights out together.

but then she just like ghosted me at the start of August and I've barely seen her this month and tried texting her and literally got nothing out of her as to why?

so I'm not sure whats going on with her and how to deal with this situation , its also possible she reappears at some point and decides to be friends with me again? but not feeling that optimistic about it
Updates
+1 y
she reappeared and I'm not sure if things are fine or not? she never mentioned my texts or replied back to them but seemed to sort of aknowledge I sent them.
How to deal with a sudden and unexpected ghosting?
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