Hello, I signed in into find my iPhone and devices appear as online but not location available. Why is that? How can I solved it? Thank you

Follow this

https://support.apple.com/kb/PH19297?viewlocale=en_US&locale=en_US

Your devices are listed below the map. The dot next to a device indicates its status:

• A blue dot  indicates the device you’re currently using.
• A green dot  means it’s online. If the device can be located, you also see the time it was last located.
• A gray dot  means it’s offline. If the device was recently online, you also see the time it was last located. If the device has been offline for over 24 hours, you see Offline.

I also cant use the mirror fuction on my pioneer 4400 nex head unit for my car