Put the summary of the bug you're having here

When in survival (or creative) and you put an EMPTY bucket into your hand, you can hold down your finger and it will highlight the water and it is unbreakable, like bedrock.

I expected that the water would not highlight as if it were a block.

Step 1: get an infinate water source going
Step 2: empty a bucket
Step 3: hold your finger down on the water
Step 4: notice how it highlights the water
Step 5: it is unbreakable, in creative it is breakable, like bedrock.