Got my answer:
* this is acknowledged as a bug in v5.6.1 and v5.6.2
* it has been fixed in v5.6.3
* it is NOT mentioned in the Release Notes for v5.6.2
* there is a CLI workaround as follows:
diag sys waninfo
When I ran that CLI command first time, it threw an error, however a few seconds later the GUI updated correctly.
When I ran that CLI command a second time, it ran okay.