Recently, OnePlus cancelled the roll out for the OnePlus 5 Oreo (stable) update due to bugs. That build was arriving as Oxygen 5.0. Now, the company has announced that the roll out has resumed. As for difference between the two builds, the new one is arriving as OxygenOS 5.0.1 and contains a couple of new fixes, presumably for those issues that caused the cancellation of the first build. The new fixes in question are for bugs related to third party camera application and network issues for European operators. Also, the update isn't compatible with units having unlocked bootloader, so...
Source: https://www.gsmarena.com/oneplus_5_oreo_roll_out_resumes_as_oxygenos_501-news-29014.php
