It’s clear what happened. Notice he’s now voting with the Dems exclusively.
I think Rand wanted the Manchin deal where Biden gave Manchin’s wife a position and then increased her slush fund budget by 5 or 10 times. Manchin came around to voting for one of Biden’s Trillion dollar spending bills after his wife got her position. Rand just wants his.
When he isn't voting with the RATS lockstep, he's in front of a camera bad-mouthing President Trump. He's certainly lost his way. Maybe he has a glioblastoma tumor where his brain should be.