the issue is not directly related to glass shattering. Some general collision logic has messed. May be something got wrong with the base collision element on "chassis" component (the most common cause). I advise to take a look whether all other collision elements on the vehicle work or not (e.g. open all doors, bonnet and trunk); shot them, try to walk through them or stand on them (bonnet, trunk). also, check collision of opened doors against peds and against static objects like light poles. If everything works fine, then you can dig into window collisions deeper. If any aspect of collision on doors/hood/trunk does not work as it should, then the "chassis" collision has failed.

Try "double collision" fix on "chassis COL" object. It usually solves issue with this object.

I have made edits to a base game gta model, But because of these edits the glass no no longer breaks.
I have the Crash flags on the collisions, and have made no edits to any of the collisions, They all have the right external id's
And the collisions themselves are default GTA base-game model collisions that literally come from a working vehicle in-game.

But every fix and thing I have done in attempt to enable the glass shattering and collisions don't work.
The bullets just pass through the glass, no fx, no sound, no impact nothing.