There can be a variety of reasons for the deterioration of a mouse sensor's function. Please take the following steps to resolve the issue:
1) If you have a SteelSeries Engine 3 enabled device, please update the firmware to the latest version. This can be done by installing the latest version of SteelSeries Engine 3 here.
If you already have SteelSeries Engine 3 installed, please make sure you have the latest version. If you do, open the Engine window and check for any available firmware update under the product headers.
2) If updating the firmware does not resolve the issue, please attempt to clear the sensor by using a compressed air can. We do not recommend blowing into the sensor or using any sort of liquid to clean the sensor as this can cause permanent damage. Do not wipe the lens or the sensor as this can also cause tracking issues.
3) If you still experience tracking issues, please try using a different mousepad or surface. For this test, we recommend using a single-color matte surface for optical mice and either a matte or glossy dark surface for laser mice.
4) If these steps still do not work, please try the mouse on another PC.
4a. If the same issue persists on another machine, please click this link to file a warranty RMA ticket.
4b. If the issue does not occur on a different PC, please file a general question ticket and provide the instructions linked HERE