Most Android devices have something called Smart Network Switch. It can be a bit buggy and will drop WiFi connections from time to time. It searches for the fastest connection (sometimes), and when it can’t automatically connect to your hotspot, it usually reverts to cellular data.
It also turns out having it on will use more network data, so generally speaking, it shouldn’t be on. Once you turn that off, you should be able to connect automatically to the hotspot. Here’s how you can do this on most Android devices:
- From the Home screen, tap the Apps icon.
- Then tap Settings.
- Then tap WiFi.
- Uncheck the checkbox next to “Smart Network Switch.”
This should help alleviate any issues you were having.