When I add solidify modifier instead of acting similar to extruding down is blows the mesh all over the place
Link to blender file: https://share.getcloudapp.com/d5uwEgrl
I have no idea how you managed to do that!
Could you please provide a link to your .blend file (via Dropbox, Google Drive, or...)?
It could be that the strength is too high. Maybe try making it a lower value(Or higher. Whichever ever is closer to 0) I'm not too sure though.
Here is the link to a blender file - https://share.getcloudapp.com/d5uwEgrl
No that's not the case, I've checked that, the issue is that the direction of solidifying is not tied to Z axis, if that makes any sense.