I use this to do hand work and it has worked fine over the years. I have it set right now to do some template work and it is/was set for 5/16" depth. Bit seems to be tight in the collect and the locking lever is/was tight. This morning as I was routing 16 spots on night stand legs to let in a wooden string that runs front to back on the side so I can screw my linear guides to it, the depth moved from the 5/16 to 3/8". I tested it on scrap with the set for the right depth before I began and to my best knowledge everything was locked down properly.

How could the bit move like this to increase the depth of cut by a 1/16"?

Thanks.

Brian