My "z" mouse has been repeating actions even though I only press the button once.

For example:

my Bottom Thumb button is "CTRL left" and its set to "press" because I need to hold it down. I have been doing this for the past 1 and a half years of owning the mouse and it has been working perfectly fine but it recently decided to keep on repeating the action with no stop to it after i only press the button once and dont hold. Does anyone know how to solve this problem? And also if any Devs see this maybe add a "Hold" setting?