UK000Y_20210421 lyrids = 16
UK000Y_20210422 lyrids = 29
UK000Z_20210421 lyrids = 31
UK000Z_20210422 lyrids = 38
Camera Z has Lyra about in the middle, while camera Y is more NNW (Cassiopeia to the right).
The software creates a "track-stack" where instead of stacking on the static ground, it stacks on the moving sky.