Jumping while sprinting with a speed effect slows player down

When sprinting on soul sand/soil with Soul Speed III boots, the player moves at 9.064m/s. When jumping while sprinting on soul sand/soil with Soul Speed III boots, the player's speed is reduced to ~7m/s.

When sprinting with the speed II effect, the player moves at 8.980m/s. When jumping while sprinting with the speed II effect, the player's speed is reduced to ~6.5m/s.

Expected behavior: Player speed should not decrease as a result of jumping while sprinting.