Button on my screen that won't go away.

There is a button on my screen that won't go away and I can't figure out/remember what it's called to disable or delete it.
It doesn't show up in screen shots but it is a grey circle with a darker grey, slightly larger circle behind it.
When I click it, it takes me to my android home screen. When I hold it down and to the left, when i let go it takes me back and goes ahead doing the same from the right.
It is preventing other apps from working probably as they keep having to stop to tell me to disable other apps "overlay" permissions.

I've looked through all my apps and permissions and haven't been able to find out where it is to disable it.

Any help is much appreciated

 

no it doesn't show up in screen shots

 

sorry, I have a huawei p20 pro

 

I was confident that this was going to solve it. I downloaded it and spent two hours analyzing every section and I can't seem to find out where it's coming from.




This is what comes up every time a site asks for my location or permission to send me notifications. I looked again through all the permissions and still had no luck. I don't want to wipe my phone but I'm thinking my options are wearing as thin as my patience.

 

SOLVED

I discovered it finally as I was looking through my settings for factory reset lol.

It was hiding in the navigation settings.

I had enabled NOTIFICATION DOCK somehow.

Thanks for your help guys!