#1
When i bend on certain frets, the sound just stops. It wont ring at all when i bend past a certain point. this occurs on multiple frets. What could this be? It isnt a truss rod-related problem, or my bridge or strings btw. its been occuring for a while, but my neck is pretty clean, and ive only had this guitar for about a year. Its an epiphone explorer
#2
push the string down harder...

its probably because when you bend up your letting off of the string a little bit
#3
Try what he ^ said, but also it could be your guitar 'fretting out'. I don't know technically why it happens but on some guitars once you get to a certain point the sound will just stop and there's nothing you can do about it apart from get the frets re-dressed or something (i'm not too sure, i don't know about the repair/maintenance side apart from putting strings on and stuff.)
#4
It frets out because the neck surface is convex so as you push up, the string loses clearance to upper frets until you effectively lose any room for vibration. The cure is to increase the action.