Hi
@Morgan214817 and welcome to the forum. I wouldn't worry about the .6 ohm reading, factory coils are mass produced and can vary by .1 or .2 at times. If the coil is a true .56 it will read .6. The resistance will or can change with usage too.
I hate to ask these questions...but
What battery are you using in the Subbox?
Did you wick the rba?
Bumping for more opinions as to the issue.