Download issues

I've been having a problem with downloading on my android phone the downloads get stuck on 100% and don't complete and when they do download I have to be on the app for them to download if I exit that tab or if the screen dims it won't download at all. Recently I started playing a random movie just so the app remains open. I have reported this to showmax and got useless advice to restart my device. I cancelled my subscription for a while and came back this month after a few weeks this problem started again. And I also have Netflix which I use on this device as well with no problems so the problem is NOT my device. At this point if I cancel again I'm not going to reactivate because I can't pay for something I can't fully use. If I'm paying to also have the option to download then it MUST download.