Renewed iPhone X with a really unique battery issue, please comment it
I already wrote a post on this singular misfortune and @Minho suggested me that the battery may be faulty (thank you, Minho - the post is “sometimes battery % stuck/frozen and it won't charge only restart” on July 8th). I bought a renewed iPhone X, it was perfect with battery health at 99% but after 1 month it started a strange fault: from time to time the battery level remains frozen and the iPhone doesn’t recognizes any charger (wireless or wired, original or not). Actually even if is apparently it is not able to recognize the charger, the charge takes place (you can feel the warm device). In the same time if I look at the graph for the battery level, I see the lack of the last statistics while there was activity (look the picture).
It looks like the battery disconnects from a software point of view but actually it is physically connected. Only a restart of the device resolves temporarily the issue. This problem is haunting me also because I can't replicate to show it when I want. Further this it seems that the issue does not appear when I remove all my personal configurations with my AppleID (but I am not sure about this latter point). The repairers return the device to me saying “no fault found” and I can't enforce my warranty rights after paid €650,00.
Of course there are some clues that point towards a SW problem but the firmware is updated to the last release 12.3
In your opinion is it a possible hardware fault? ... or software fault? Do you know if the battery has an electronic embedded assembly that could be the responsible of this kind of fault?
What other check can I do? I could replace the battery by myself but I don't know if it's the right strategy. Please your comment will be much appreciated.