Problems with new battery calibration?

Hello everyone!

I just changed the original battery in my 15” early 2013 retina mbp running macOS Mojave 10.14.6 with one bought from iFixit.

The substitution went fine and everything seemed OK: the new battery outperforms the original one in capacity (8626 mAh, at the beginning it gave something like 8860 mAh, then it dropped to 8626 after the first cycle) and doesn’t exhibit sudden discharges, BUT… I calibrated it following the instructions given here on the iFixit website and before completing the calibration the readings between the system remaining charge indicator were almost spot on with CoconutBattery and with the charge in mAh indicated in the system report - energy tab.

What’s strange is that this three indicators line up when the battery has lowish charge (say less than 45%) but drift as much as 5% when the charge is over 50% (from the system indicator), with the drift getting bigger as the charge increases. This happen both during charge and discharge.

Right now the computer is plugged in, I have green light on the Magsafe, 100% charge on the system indicator, but both CoconutBattery and the system report tab says the battery is still charging…

Already tried to reset SMC, NVRAM, etc.: no luck. Shall I repeat the calibration process again? Is this something I should worry about?

P.S.: Now both CoconutBattery and system report says battery is fully charged but still charging…