Cloth simulation stuck at frame #20 for a while before moving to the next frame

Hello everyone, when I set cloth simulation and hit the play button, the timeframe indicator goes from frame #0 to #19 in the speed 1f / 0.5s. And when it is at #20, it stops there. If I leave it and come back 30 minutes of 1 hour later, the cloth simulation will be done. But why it happens? Anyhow to fix it?

I use Ryzen 7 3700x and RTX 2080ti.