ipad won't drop hotspot connection when screen off

I use my iPhone hotspot for my iPad connection. However I do not want it to be constantly connected to the hotspot when the iPad is idle or not in use. Currently my iPhone hotspot is always connected by my iPad and it won’t drop the connection when it’s locked.

i have auto lock on the iPad on. And auto connect on. It will initiate the hotspot on my iPhone automatically when it’s on. That’s good but I also want it to drop off the connection when it’s not in use to save battery on my iPhone and also not to constantly see the green highlights on the top left corner indicating hotspot is connected to a device.