I have Huawei Honor 7 Lite / 5C (NEM-L21). I don't want my phone's screen to auto rotate, so I have it off. But randomly, it turns on. That also happens to WiFi. This started few days ago, I haven't upgraded my phone. It's few months old.
I would think that it is system bug. Huawei, Xiaomi and (non Nexus) LG have worst implementations of Android. There are tons of bugs in their customizations.
I don't understand how they can pass Google's certification.
Disclaimer: I'm developer so I get many bug reports from users owning those devices.