Can't send SMS on Dual SIM Phone

I recently bought a dual SIM phone and find that if i try to send a new message to a contact or cell phone number it will not send it. It just sits in a trying to send state. If i send or replay to someone that i have sent to or received from before there are no issues. It seems that the app does not know what the default SIM send account is..

The phone is a Xiaomi Mi 4i running Android 5.0.2

I recently bought a dual SIM phone and find that if i try to send a new message to a contact or cell phone number it will not send it. It just sits in a trying to send state. If i send or replay to someone that i have sent to or received from before there are no issues. It seems that the app does not know what the default SIM send account is..

The phone is a Xiaomi Mi 4i running Android 5.0.2

You've put 2 SIM cards in the phone? Are you using AirDroid Win/Mac or AirDroid Web when you encounter this?