As compared to Version 1.20.6 and earlier, ender pearls fly significantly farther (up to around 20 blocks farther based on my tests) when running and jump-throwing.

I create "ender golf" courses that require precision ender pearl throwing. The "holes" are limited by the maximum distance a pearl can travel. Many times, a player will sprint and jump-throw to achieve the most distance. Minecraft players sprint and jump-throw for more distance in normal gameplay, too. In version 1.21, this distance the pearl travels is much greater, thus my ender golf courses are rendered incompatible with new versions. When standing still, pearls travel the same distance as in previous versions. It's only when jumping (slight effect) or sprinting and jumping (large effect) that you see a difference.

To reproduce:

• Load version 1.20.6
• Create a superflat world
• Mark a starting point (from which you will throw)
• Sprint and jump-throw consistently from the same spot with the same angle (facing the same direction)
• Mark where you land (repeat many times)
• Exit and switch to version 1.21
• Load the same superflat world, throw from the same spot in the same way
• Observe the pearl sails over the old landing spots

In the attached screenshot below, I throw from some spot out of the frame to the left and land in the colored squares. I throw standing still (pink), jumping (blue), and sprint-jumping (red) in version 1.20.6 (upper row) and 1.21 (lower row). Notice the huge difference sprint-jumping.

I'm more than happy to provide more info; I am a bit of a rookie when it comes to bug reporting. Thanks to the developers!