Current speed is not showing in the status bar

My RAM File System doesn't show anything for the current speed in the status bar, under "Click to switch between session totals and current speed". Is this correct behaviour?

The Current Speed display is empty:
https://i.postimg.cc/0Q7GRJBD/status-bar2.png

The Session Totals display shows the total numbers:
https://i.postimg.cc/RV7YQWCB/status-bar1.png

The current speed is displayed while copying files to/from the RAM FS volume. If you currently aren't copying anything, there is no current speed.