Re: Not sure anyone should care
I know that different people/different devices but...
Presuming you mean either KeyOne or Key2 then there were some issues when first launched but I don't recognise the above as any of those and I have not experienced what you list myself. I am not saying these phones are the best ever but if your needs are good call quality/decent battery life and a physical keyboard then there are very few competitors.
I would be thinking of doing a full reset to ensure there is not something gaga within the Android side, especially with your problems in Whatsapp as if the app is active in background you should get a notification of a call with the option to answer.