Question about panel applet not working

[Bret Busby]

Hello.

I am running Linux Mint Mate 21.1 on a computer that has a USB WiFi 
dongle thingy. I believe that this problem is a problem involving Ubuntu 
or Ubuntu Mate utilities.

Control Center -> System Reports -> System Information shows the network 
device to be

"
Device-2: Realtek 802.11ac NIC type: USB driver: rtl8821cu bus-ID: 
3-14:6 chip-ID: 0bda:c811
   IF: wlx90de8039844b state: up mac: <filter>
"


Now, the problem is this; the network interface works okay, but, in the 
panel, in the Mate Netspeed applet, whilst the information of the device 
can be displayed by doing a mouseover of the applet, or, right clicking 
(using the non-dominant mouse button) on the applet, the applet displays 
receive and transmission rates of zero, whatever rate is occurring, even 
when it is in the MB/s. The applet had worked okay, when USB tethering 
was used, showing the connection as an Ethernet connection, but, using 
the USB WiFi dongle, it will not show data transmission speeds.

The System Monitor (GUI thing) shows receiving and transmission speeds, 
for the USB WiFi dongle, but, the Netspeed applet does not.

Is it possible for a simple person like me, to get the Netspeed applet 
working for the USB WiFi dongle, and, if so, how (stepwise, for 
simplicity), or, is this a systemic problem that needs the developers to 
resolve it (if they would be inclined)?

Thank you in anticipation.

..
Bret Busby
Armadale
West Australia
(UTC+0800)
..............