Fracture Mode Mesh Acting Strange!

Hi there,
Really hard to look for the solution to this problem on google/YouTube, please help.

I’m trying to practice breaking glass with Fracture Mode and a cube shape for a project and for some reason these grey edges are popping out everytime I select the fracture type. Upon trying to play with parameters, it begins to blow out as you see in the photo.

I understand I’m supposed to play with settings but I just don’t know how to go about fixing this particular issue. Its not coming up in any other tutorial I’m finding.

Any and all help I would gladly appreciate. Thanks for taking the time!