Buffering Blue Circle Why !

Hi all was just wondering why i always get the blue circle and buffering when the cams are trying to load on my iphone 7 plus, It is starting to get very annoying now after all the money we spent on two cameras and all you get is buffering why ?And why does the camera colour go all weird and pixelated too i have taken a screen shot of it when it go's all funny, I have even been in touch with Bt about my wi fi and they say it coming into my boundery ok at 50 megs, So why wont the cams load on my iphone 7+ and the app drains the hell out of the battery it can go from 100% down to 5% in a hours that fault need adressing i think for folk using it on the phone !Ive read a few of the article's on here but no answers