In Doom Patrol Weight of the World’s #1, Cliff is human. I don’t remember that happening in the previous 2016 DP series Gerard Way wrote. Isn’t this series supposed to be a continuation of that one? Maybe I missed an one issue.
It happened in the Doom Patrol/Justice League Special at the end of the Milk Wars crossover. If you haven’t read that I highly suggest reading it. You can find it in the comics section right here: DC Universe