I’ve looked in the help, Googled, etc and have not been able to find reference to it.
I contacedt support and this is what they said
The locking block is the setting of the origin position. （This means that you can choose to set the origin position at A or B
.It’s just a UI icon that tells you the set origin position.
Still confused. Set Origin lets you choose the origin (Bottom Left, Center, etc.)
What does Locking Block Yes (A?) vs No (B?) change relative to that?
I found it changes the work piece size.setting
I noticed that, I think it’s a bug. It jumps to 400x400.