Dual Monitor software (Displays) causes mouse lag and eractic mouse

I am running two HP computers, A and B, with two monitors each.
Machine A was running Ubuntu 16, since 2017, two HP monitors via DisplayLink plugable usb 2.0 display adapter. This ran well for years and 16 was preferrable to the changes in 18 and after.
Machine B was running Xubuntu 16, two identical HP monitors via a DisplayLink plugable usb 2.0 display adapter. This ran even better and we did not have a reason to change anything.
In mid-December 2021, on Machine B, after both 'software updates' and an electrical outage, the mouse started behaving erractic when the second monitor was on. There were not any problems just using one monitor.

  1. when moving and it paused, it would leave a ghost pointer showing
  2. it would sometimes leave pointer 'trails', much like some old mouse setting in windows3
  3. it would carry small (a few mm) squares of pixels and leave traces
  4. mouse lags, starts and stops and 'jumps around'

After trying a few fixes to no avail, I 'updated' to Xubuntu 20. The problem persisted with slight variations. No problem with single monitor.
I then did a complete new install from a MATE 20 live usb. Same problem, with a very slight improvement. No problem with single monitor.
I then 'updated' to MATE 21. Same problem. No problem with single monitor.

With nothing else to try and liking the look of MATE 20, I installed it on Machine A, in a new partition. Machine A did NOT suffer from the electrical outage.
With second monitor on, A has a different problem. If the second monitor is used, the mouse lags and moves eratic. (Has the look of a system that is low on resources and is struggling.) No problem with single monitor.

I have tried all the settings in various combinations, mouse and displays, installing Arandr, with no improvements. I've attempted various things from the web, 'zoom' settings and nvida monitors...... nothing works as of yet.
It all seems to be related to the 'new' DISPLAYS software?
I'm surprised that my two computers seems to be the only two with this problem.
Any help would be greatly appreaciated.