you manage to watch playback , but have trouble downloading alert vids?
watching playback ( when your phone is connected to the same wifi as the cams) involves little use of the web, data is transferred point to point from camera to phone.
however the alert video clips download from the cloud.
as a test try switching to 360p from hd & let us know.
if it’s playback that’s an issue for you have a look at this thread to see if it’s related to the problem affecting my setup