If a player was pushed (from a high place) by a piston with a slime-block immediately after respawning from a spawn point set by a bed, the player takes zero fall damage from falling.
If a player was pushed (from a high place) by a piston with a slime-block immediately after respawning from a spawn point set by a bed, the player takes zero fall damage from falling.
The player is invincible for a few seconds after respawning. This is an intended feature.