object disappearing after using Boolean modifier posting this as other post wasn't of help.
i've tried applying all transforms on both object
increasing poly on both objects.

checking and flipping normals on both objects.
I did a bit of experimenting on your .blend file. Turns out that if I go into edit mode on the cylinders, press P&gt;By Loose Parts (To make them different objects) and then move them to a new colloection, and then set the boolean type to collection and put in that cylinder collection, the boolean works and doesn't make the mesh disappear.