I'm able to re-create this bug on 1.14.4-pre4, it's especially noticeable when sprint jumping while holding left click to break grass as it also kills the upward momentum of the jump (allowing jumps lower than 1 block). This does not seems to be linked to framerate dips as frametime graph remains stable.
the bug happens when holding any seed in the right hand and bone meal in the off hand and right clicking on any planted seed, tried on 1.14.3 and 1.14.4-pre4
I'm able to re-create this bug on 1.14.4-pre4, it's especially noticeable when sprint jumping while holding left click to break grass as it also kills the upward momentum of the jump (allowing jumps lower than 1 block).
This does not seems to be linked to framerate dips as frametime graph remains stable.