Logic Pro X - dragging midi automation down in piano roll below zero

When editing midi automation in the piano roll, I want to select a portion or all of the automation and drag it up or down to relatively adjust the automation. However, whenever one part of the automation hits zero or 127, it stops and wont let you drag it any further.

See below pics. I can adjust it relatively between zero and 127 but as soon as one part of it hits those limits it wont let you drag anymore. I know you can do it because it used to allow me to do it before on my previous machine. I've looked everywhere for how to do it but gotten nowhere.

Wondering how you activate or allow that?