Backing up the full Bitcoin Blockchain over to another HDD.

Guys, I have a HDD where I have a full version of the Bitcoin Blockchain and its all synced up (i.e it's a full node). Let's call this HDD "A".

I then copied all of the data over to another HDD that I have via USB 3.0. (It still took 2 hours). Let's call this HDD "B".

HDD "B": As you can see all of the Bitcoin Blockchain data has copied across to HDD "B", the full 532GB of the node.

So why when I open up HDD "B" does it want to re-sync from the start all over again??

The data is already there on HDD "B", why can't it just re-sync from where the HDD "A" left off.

"Scammers don't bother"

Thanks.