New Sub - 7 Seconds Slow

[XplorerII]

Hello gang!

First post on TRF, and first "new" rolex purchase I've made from a local grey market dealer.. shop has been in business for a few decades, nice part of town (not a shady flea market).

It's been less than a week of ownership with daily/nightly wear, and I'm already noticing it's running about 6 seconds slow (as I am checking today). Is this normal/is there a break in period? Warranty card dated a few months ago. Was pretty OCD while inspecting the piece prior to purchase to ensure its authentic.. e.g examining the laser etching under magnification, etc.

Would love to hear your thoughts or suggestions, would like to avoid taking it to an AD or having it get popped open by another third party watchmaker if possible to verify authenticity of the movement and/or make any adjustments to regulations... I understand I may not be able to have it both ways, but do want to see if you have any input before I take any further action.

Thank you!