Picking it up works, but when you place it somewhere else (maybe modify it by extending the pipe?) it creates a ghost block in the original position. This makes you unable to use this block for anything

In this case it was a fluid pipe containing steam...

There is not much we can do about this aside from preventing the pipes from being picked up.

To fix your issue, make sure debug commands are enabled, and then you can use the /mi pipes <pos> clear command to remove the ghost pipes.

Looks like CarryOn uses tags now so the carryon:block_blacklist tag could be added to the pipe block to prevent this issue in the future.