Replaced battery percentage dropping from 70% down to 7%

Hello every one,

15th of last November (2019) I've purchased a battery for my MacBook Pro (Retina, 15-inch, Late 2013) : MacBook Pro 15" Retina (Late 2013-Mid 2014) Battery

Since I didn’t have time to replace the battery immediately whet it arrived I replaced it this week end (25th of January).

I strictly followed the instruction on website: Sostituzione batteria nel MacBook Pro 15" Retina Display versione fine 2013

The whole procedure with replacing the battery went fine I have also fully charged it and leave it on charger for 2+ more hours. When I started the discharge phase it all looked okay until the state of charge dropped instantly from somewhere between 80 - 70% (charge remaining at that point was about 5600 mAh) down to 7% (500mAh). After approximately 10 - 15 minutes system reported low battery and the capacity was somewhere between 300 - 500 mAh.

After that I discharged the battery completely (I wait for MacBook to shut off) and leave it at that stage for the whole night. In the morning I have plugged in the charger and leave it turned off and charging until the light changed from orange to green than I turned it on and left it on charger for another 2 hours. After that I made another discharge cycle but the same phenomena of dropping SOC from 70% to 7 % occurred again.  (showed on pictures bellow - pay attention on the date and time)

After that I tried to reset the SMC but it didn’t help.

I also tried to unplug the battery hold power button for 30 seconds and connect it back, resetting SMC and did the whole “calibration cycle” again and it also didn’t help.

Any help would be much appreciated.

Additional picture just after SOC dropped and charge was connected:

Thanks!