For LHC Run 3 data taking the track reconstruction algorithm used for the ATLAS Inner Detector has been optimized with a particular focus on minimizing the number of erroneous and low-quality (fake) tracks processed by rejecting them as early as possible. This ensures a collection of high quality tracks to downstream reconstruction and physics, a key aspect in ATLAS. This document describes the modeling of track reconstruction in the core of the jets, presenting new measurements of the charged particle reconstruction inefficiency and fake rate inside jets. The measurements rely on $\sqrt s = 13$ TeV LHC Run 2 data reprocessed with the software that will be used for LHC Run 3.