iphone - is the hotspot isolated (can you see other devices)?
Personal Hotspot is designed for sharing a cellular data connection, not for acting as a wireless access point or router. This means that multiple devices connected to the same iOS device cannot connect to one another - they can only access the Internet (assuming the cellular data connection is active). Unfortunately I can't find any Apple documentation to confirm this, but have seent his from personal experience.

Your best solution is to purchase a portable wireless access point and connect all of your devices to that.

Hootoo makes a dependable and well supported line of travel routers starting at $20. Models get better features and even built in batteries for another $10 and $20 respectively. 


https://www.amazon.com/HooToo-Wireless-Performance-TripMate-Hotspot/dp/B00HZWOQZ6