WiFi graph TaskManager blank

Minor irritation after in-place upgrade to 20H2 19042.631
Resource monitor shows numerically and graphically the network throughput as normal.
Task Manager no longer shows the graph (it is there and update speed checked, changed, paused, reset to normal).
Task Manager still shows network throughput in Kb/s ( Oh yes ... rural copper here ).
Prior to upgrade was always able to see the graphical version.
CPU, Memory, Disk, GPU all showing graphically.
Not a big deal but always liked to see the graph (just to depress me I suppose).

Thank you - dalchina.
Bullseye.

OOPS ... why not close it and start it again ?
Ah yes ... that works !
So have WiFi ......
But now have two extra graphs ....
vEthernet(Ethernet) with no throughput ... nothing plugged in.
vEthernet (WiFi) showing no throughput

Not using HyperV (never have) but I believe it is enabled on this machine.

Thank you - dalchina.
Checked Windows Features and HyperV is not active but found the post by Kari to completely disable it so will use that later.
Regard this as solved - thanks.
Paul