open G string buzz

You can put the saddle back to where it was if you haven't done so already.

Is your string underneath the string tree?
Also, check to see if you have loose screws on the tuners as well & get back to us.

 

Just trying to get the basics out of the way first.

Strap locks vibrating?

Check ALL of the screws on all of your saddles (and ALL tuners for that matter) & make sure none are moving freely... i.e. they make contact with the bridge plate and don't vibrate. Sometimes they'll only vibrate at the right frequency.

Check the width of the slot in the nut. The width should be relative to the others. If it isn't, you can get by for a short time by sticking a piece of paper there. By short time I mean: "I have a gig tonight".

Here's the one I was avoiding when reading your post. Give a rather hard succession of raps (with nuckles... no tools) to the back of your neck with the strings on AND off. If you feel and/or hear vibration, it could be your truss rod. Don't freak out. We can't tell for sure over the internet. A loose (hopefully) or broken (not the end of the world) truss rod can make those vibrations under certain frequencies... or ALL frequencies(but not in your case).

A truss rod malfunction will make the entire bass vibrate in an unfamiliar, disconcerting way.

Check your setup and make sure you have your rod engaged. i.e. not slack and actually doing something.

Again, don't panic. It could be the nut, or something else which I am forgetting to mention.

 

Phew!

You'll need to have that replaced. You can order one pre cut for your particular bass, cut one yourself (if you are brave) or take it to a tech.

If you do replace it yourself, pre cut or otherwise, don't use super glue or any other permanent glue. White or wood will work. Pretty much only has to stop it from vibrating & moving sideways (sideways not really an issue with your bass). Also, you'll want to be able to remove it without a jackhammer if something else goes wrong with it.

A tip: when you are re-stringing your instrument don't let the string drag inside the nut slot. When it gets tight, hold it up with your fingers as long as possible to minimize the sawing action on the nut.

This might not be your case, but I've seen and done it myself (long ago) before

 

or you can simply raise the nut slot by using a gel super glue, thin layers of over a day or two and you will be golden my child