Hi @Dave Goodell,
Welcome to Microsoft Q&A forum.
Thank you for reaching out. I’m sorry to hear that your cursor is moving erratically, especially since even a brand-new Arc Mouse hasn't resolved the issue. I understand how disruptive this is to your workflow.
Since the problem persists with a second device, the cause may be related to environmental interference or a system setting rather than the hardware itself. To help me narrow this down, could you please let me know:
- Does the cursor move on its own even when the mouse is turned off?
- Are you using an original Microsoft power charger or a third-party one?
- Is the Surface connected to a docking station or USB hub?
While we wait for those details, please try these three quick tests:
1/ Test the Touchscreen:
- Go to Device Manager > Human Interface Devices.
- Right-click HID-compliant touch screen and select Disable device.
- Check if the mouse starts behaving normally. (You can re-enable it the same way).
2/ The "Surface" check:
The Arc Mouse uses a specialized sensor that can be sensitive to specific textures. Even if it worked before, please try using the mouse on a plain piece of white paper or a dark, non-reflective mousepad to see if the jittering stops.
3/ Isolate the power source:
Unplug your Surface from its charger and any external hubs/monitors so it is running strictly on battery power. If the mouse stabilizes, the issue is likely electrical noise from a power cable or peripheral.
Please let me know the results of these tests and the answers to the questions above so I can determine our next steps.
Looking forward to your updates.