When using NBT pick block it does not grab the new data from a block if it has pre-existing data

How to reproduce

1. Place a command block down and enter `say t` into it
2. Use pick block on the `say t` command block and place it down
3. Change the `say t` of this newly placed command block to `say c`
4. Use pick block on this `say c` command block
5. Place it down, and observe that it still says `say t` even though we just changed it to 'say c'

Expected results

When you grab a block with NBT pick block it should have the data of the block you selected