Created attachment 111172 [details] 25sec video demonstrating parts of the issue. I have had my computer on for abour sixteen hours and now the desktop network monitor widget has frozen. The other widgets which are CPU Load Monitor, Hard Disk Space Usage and Memory Status still work and updat themselves. When I right clicked the widget and could choose what itnerface to monitor I could not see my wireless so I selected my ethernet which then suddenly made the wireless show up.
I have been using 5.13 (now 5.13.3) under Arch and I have not seen this behaviour anymore. If it is still present in 5.12.* I do not know.
closing as per comment 1.