About the space mouse, please contact support. It will help to know what 3D mouse you are using as well as the cable, e.g. USB 3.0. And it also helps to know whether you are using more than one screen, Windows 10 and last update, and version of VC software.
I can test on my computer with VC 4.2.2, but the SpaceMouse I can test with is very old. In the past I have come across something like you described… maybe like a year or so ago.
Other things to review are the logs on your computer for VC product (support can do that) and the SpaceMouse backstage options you are using.
What you described sounds like a bug, perhaps zoom sensitivity and update rate cannot match the render of 3D world or memory issue… is VC using Nvidia on your computer or integrated graphics?