Don’t worry, this is a fairly regular and normal occurrence, especially with the drive wheels.
There are several solutions to remedy this:
- Often the axle nut is too tight and will cause one or more bearings to click. Using a skate tool, tighten the nut until it is tight and then back it off a quarter turn or so until the clicking stops but there is no lateral movement of the wheel.
- Another remedy is to use a little white lithium grease on the bearing seats (where the bearing rests in the wheel).