Issues with jerking while idling

Already texted my mechanic, and for the record my ABS is out and I’ll need a new module so I wouldn’t be surprised if this issue is tied to that. Anyways, whenever I fully brake and go to idle forward my jag will jerk forward. Doesn’t happen 100% of the time but enough for me to notice. Only happens after I fully brake and if I put my foot on the gas it’s not an issue. I drive a 99’ jaguar xj8 for the record