Monitor seems to sleep and awake on its own

Noticed just over the last few days that my monitor seems to sleep and awake on its on. Normally when it sleeps, one needs to just move the mouse to make it come on.
However, the monitor seems to come on without anyone touching he mouse.
Only recent change is that we switched the mouse to a previous version, but it is plugged into the USB port on the front if the PC rather than the back.
Could this be causing the issue the fact that it is connected to the front USB port?