If the Judge makes no finding of true or untrue as to a new law violation that is alleged as a violation of a condition of probation, but finds other new law violations true. Is the prosecution precluded from pursuing the new violation that the Judge made no determination of true or untrue regarding? If prosecution is precluded and that was not the Judge's intent, what is the procedural device to attempt to undo the harm assuming court made findings less than 30 days ago?

I don't see any reason you would be estopped if the Judge made no finding. The fact that it was alleged in the MTR but not ruled upon shouldn't matter....

Collateral estoppel only applies to fact findings. If the judge made no fact findings, then you wouldn't have anything to apply it to. I think you're good.