Block obejcts are on layer A.
You want to place the block on layer B? Ensure layer A and Layer B are both on/thawed/unlocked.
If you are new to AutoCAD, the proper and most common sulotion is to:
- Create Blocks with their objects on the layer they need to be
OR
- Create the blocks with their objects on layer 0 (that's zero) then place the blocks on any layer you want. Remember to always leave layer 0 on/thawed/unlocked and never ever draw anything on layer 0 that you may need to turn off/freeze/lock.