I think I know exactly what your problem is because the same thing happened to me.
If you remove the top of the router. You will have to remove the sliding lock/unlock button first then the screws on top of the cover. Remove the cover and look straight down the centerline of the shaft of the router if you can see it. If not you have to remove the keeper for the shaft locking mechanism first (don't let the springs fly out) . You will likely notice that the flattened end of the shaft that fits into the locking brake has broken off. This is caused by having to use excessive force to remove a bit while the shaft is locked then snapping the flat shaft end off. Most likely cause of the bit not coming out is that it was seated too low in the chuck. Always make sure there is at least 1.8" clearance.
I have never replaced the shaft if it is even possible but wish you luck nontheless.
If you remove the top of the router. You will have to remove the sliding lock/unlock button first then the screws on top of the cover. Remove the cover and look straight down the centerline of the shaft of the router if you can see it. If not you have to remove the keeper for the shaft locking mechanism first (don't let the springs fly out) . You will likely notice that the flattened end of the shaft that fits into the locking brake has broken off. This is caused by having to use excessive force to remove a bit while the shaft is locked then snapping the flat shaft end off. Most likely cause of the bit not coming out is that it was seated too low in the chuck. Always make sure there is at least 1.8" clearance.
I have never replaced the shaft if it is even possible but wish you luck nontheless.
