Call Graph in Pycharm impossible to navigate on Mac

The scroll bars disappear, rendering the Call Graph unusable after trying to scroll/navigate the graph using Mac's trackpad. Successfully reproduced on co-workers machines.

PyCharm 2018.1.1 (Professional Edition)
Build #PY-181.4445.76, built on April 9, 2018
Licensed to Propeller Health / Austin Lee
Subscription is active until September 21, 2018
JRE: 1.8.0_152-release-1136-b27 x86_64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
macOS 10.13.1