CMF1_hacker There can be another possible reason. Its possible phones manufacturing of phones might be outsourced to different companies and the phones sold in different countries might be coming from different manufacturers. In that case, based on the availability of various components devices might end up getting slightly different components inside. It can be anything like a capacitor or regulator made by different manufacturer or having different part number or something like that. Which can again mean issues can be localized based on a specific batch or manufacturer.
Just because you or me are not having issues, doesn’t mean everyone is not having it. The complaints can be genuine as well.