Unable to scroll or navigate curve editor to view curves which are going below the range

Steps to Repro
1. Create a new Project
2. Hierarchy > right-click
3. Audio > Audio Source
4. Expand 3D sounds settings
5. Twist handles on a key so that the curve drops below range

Actual Result:
Cruve goes below the range and there is no way it can be viewed

Expected Result:
Either user can scroll or zoom out curve editor to view curve or curve doesn't go below the range/graph

Note:
1. Keys don't go below the range/graph
2. Same occurs for other curve editors as well

Environment:
Windows and Mac

Occurring with:
2019.3.0a1, 2019.2.0a14, 2019.1.0f2, 2017.1.5f1