IDE hangs after switching branches

Problem

Check out a Git branch by any means in the UI. The IDE freezes or gets significantly slower. Sometimes it checks out successfully, but takes minutes to do that (5-10 mins).

The following dialog is shown when the IDE hangs - Open editors and positions:

Resolution

Add the following JVM option to the IDE's vmoptions - Help > Edit Custom VM Options and restart IDE: -Dsun.awt.mac.a11y.enabled=false?