As things are and have been since 2015, this set of circumstances screams (Marriage for immigration purposes only) Perhaps it's not, but that's how it will look to both USCIS and a Consular Officer....UNLESS....they find a way to spend significant time together, multiple times, with at least a couple months together before filing another petition, then significant additional visits between filing and visa interview.
An attorney cannot manufacture relationship evidence. The couple must behave like people in genuine marriages behave. That would represent a tremendous change in mostly the life of the the US Citizen Petitioner.
Divorce and trying a K-1 visa, will absolutely assure failure. Don't spend another second thinking about that.