Trouble adjusting splines

When adjusting splines after awhile the cursor gets stuck in some kind of rectangle selection mode. I can’t move the spline points anymore, are at least sometimes it takes many click attempts to select and move a spline point. Even more crazy sometimes I click on the inner spline point but the outer spline point moves instead - and it only moves in a tangential direction. It doesn’t matter wheter I use tablet or mouse.
Have to restart Silhuette to fix it, then it works for awhile again.

Windows 10, Gigabyte TRX40 Aorus Pro Wifi
Wacom Intous tablet, driver 6.3.20-7 (the latest Wacom drive just doesn’t work…)
Silhuette 2020.5.3

I have had the “can’t move the spline point problem”, too, and thought it was my Wacom pen sticking. I think if I click the R-click button on my Wacom pen I can make the problem go away. I can’t repro it yet.

Mac 10.14.6
Wacom driver 6.3.38-3
Silhouette 2020.5.4

If you can narrow down a set of steps that reproduces the problem, it would be very helpful.