Pis is still 1st place, both among youth and in general. Thats what counts.
1st place doesn't mean anything in Polish politics, what matters is having over 50% of the available seats. Winning here is defined as whoever gets over the line, not who won the most votes. PiS had a lead of around 13% in 2015, now they're down to 7% and even less among young people, and they lost a huge amount of cities in the first round.
As it stands, PiS are a long way away from a majority next year.
Besides, regional elections don't matter nearly as much as the parliament and presidential elections.
They matter a lot. Regional governments are probably the most important source of decision making at a level people understand, such as hospitals and public transport. They're also responsible for distributing a lot of EU funds, which are hugely important in smaller towns as there's no way they can afford to make big investments by themselves.
Well 60k people did show up to the march in warsaw organized by them.
Yet they didn't win a thing in these elections.