Makita router sparking

I finished a profile cut yesterday afternoon and the Makita was running as normal but when I started it up today it seems to be sparking from one of the brushes. When I pull the brushes out they don’t look terribly worn, the router has seen some pretty decent use since I got my Journeyman in August. Does this seem like I just need a brush replacement?

Dust or corrosion maybe?

Try the brush replacements anyway if you’re able. Sounds similar to an experience I had with mine where one seemed to wear faster than the other.