I faced with an issue on touch devices and with Leaflet 1.9. Polygon is freezing after first redraw. It looks like _currentLayer stops to receive drag events.

But I cannot reproduce this behavior on desktop browsers. I suppose it's affected only touch browsers. I'm not familiar with Leaflet and I have not enough time to dive deeper to research why behavior is different. So, I suggest linked PR as quick fix. Also, I've updated playground only for test purpose. When you accept PR I'm going to rollback all changes in this directory.