In your game agains't Arsenal you had a real problem on the wings. Arsenal's fullbacks won many second balls and intercepted loose clearances because the defensive wingbacks were busy keeping an eye on the inside forwards. A second problem appeared when your defenisve wingers pressed insidewards, these left a huge gap on your wings that could be exploited with good diagonal balls.
In this case, Smith Rowe had no trouble orienting himself and splitting your defense with a throughball to Martinelly. Gosens playing as a centreback found himself too high up the pitch at times, which created a hole on your defensive line for Jonathan David. If I were you I would either drop Ajer to a DMde position and role, or tweak your defensive line like so: BPDde-CDco-CD-de
You did not fare too bad on the ball but your centrebacks were too eager to send long passes to Esposito, which lead to unnecesary turnovers, Luiz Felipe was the worst offender in this regard. Adding play out of defence as an instruction might help you reduce this losses of possesion.