Strange mouse behaviour

Host Mac is an 16Gb M4 Mini, running OSX vTahoe 26.5.1, VM is Parallels v26, Windows 11 Pro 25H2, OS Build 26200.8655

Unless I enable mouse trails in Windows, I can't move the mouse pointer between the two screens. At least when I do enable Mouse trials, the wheel actually works. Our ERp application makes good use of thr mnouse wheel, and not having what's a very basic feature these days is annoying to say the least.

I know this is a simple problem but I just can't find a suitable fix for this, and it's frustrating. As a mid range IBM Power platform application programmer, I find it hard to belive that this combination of VM and Win11 hasn't been "pen" tested at all. Or are the end users the actual beta testers as well?