Your cabling sounds more than sufficient.
Your first post stated that you were charging to 3.35V / 13.4V but this only got testing voltage to 3.28V / 13.12V which is only about 60% SOC based on the most popular SOC% vs. voltage tables.
Now you are charging to 3.6V / 14.4V which is getting you to a resting voltage of 3.37V / 13.48V or 13.4V for the battery.
At 13.37V / 13.48V, your battery is close to 97% SOC based on the most popular tables, and at 3.35V / 13.4V, your battery is at ~90% SOC based on those same tables.
So it looks to me as though you’ve solved your issue if your goal was to get to ~90% SOC and you may even want to back off a bit to a bulk charge target of 3.59V / 14.36V or 3.58V / 14.32V if you don’t need that last 4-7% and you are concerned about stressing your battery more than you need to…
Every 10mV is significant once above the knee and if your target is ~90% SOC, aiming for a resting voltage of 3.35V per cell or 13.4V for the battery after your 5-minute CV period has ended and charge currents have ceased should fit your needs…
