Unfortunately there is no direct way to "re-sync" the game on the fly. That is because when it happens, a domino effect of other events will happen with it, even the rounds.

You could however try detecting when the round ends on both ends (when they happen independently) and force the round to restart using a combination of OnRoundEnds event and photon events. Once its detected on both builds, you can try toggling "UFE.config.networkOptions.allowRollBacks" to disable rollback.
If you want a more precise detection you can try enabling the desync handling tool and looking under FluxCapacitor.SynchronizationCheck for how it works and what to do when it happens. By default, both builds freeze and a recording tool shows up for debugging purpose.

Desync is probably one of the hardest things to debug on UFE for the code complexity alone. Ideally you want to have some kind of version control and be on the look out for changes that can potentially cause network desync and revert when necessary.