Deavan and Jihoon have volatile fights on 90 Day Fiancé: The Other Way, so this could just be a tiff between the two that they’ll ultimately work out.
A video from Deavan Clegg and Jihoon Lee’s vlog doesn’t appear show her wearing the ring on August 3rd, but she is clearly wearing the ring in a video prior to that on July 23rd.
Whatever happened between the couple may have been recent.
They could also be intentionally fooling viewers to keep them invested in the story, and we really won’t know anything until confirmation comes from one or the other on the state of their marriage.