It’s possible it could be a hardware issue with the mouse, if you try to drag an icon around on your desktop, does it ever let go? A troubleshooting step you can try is a capacitor drain on the mouse:
- Remove the battery from the mouse.
- Randomly click on all of the mouse buttons repeatedly for 15 seconds.
- Reinsert the batteries and test the mouse.
If the problem continues you may want to test it on a second PC, if it happens there then that would confirm it as a hardware issue, in that case please contact support.