Doogee F5 'Usage Access' - anyone else??

My Doogee F5, when I install an App that needs to automatically start up when the Phone boots requires Usage Access. I tick the box and it works no problem. Then when I restart the Phone it does not auto start up and I need to grant Usage Access AGAIN as all the boxes are unticked again! This basically renders several several Apps completely useless and I had to delete them (examples: Omni Swipe, Phone Leash, Macro Droid). So this is a very big problem indeed which I'm hoping will improve with your Android 6.0 update? I don't think so as I've also got a Nexus 5 with 5.1 and it's usage apps work fine. Or am I missing something here? I emailed the company, no reply. Messaged and commented them on Facebook, no reply. I am pretty shocked at such a useless customer service. There's no way to raise bugs and issues. They just think we all have to get on with it ignoring them. And this is a pretty big flaw in my opinion. If anyone can help please share it will be much appreciated. Thanks.