Is that a default that a mission is a fail if log out or disconnected to internet?
I keep on wasting time to run a mission and disconnect to internet, and the mission is hold, not as a fail, cannot continue to run the rest of the mission, nor the mission getting re start.
Only I can do is press abort to fail the mission if I want to run another mission, and the mission which was running is dead.

Would you please tell me I have to spend hours on a mission on an Android device, cannot continue if I disconnected to internet and abort mission is my only option?

Only some missions do that. It'd be nice if they all said at the beginning.

Strongly agree......

What is the name of the mission?

Usually, any mission involving the spawning of bots, like escort or hive or skirmish/battle missions tend to fail you on logout. Other missions, like timed missions also would.
It's up to the mission to fail you on logout.
It is a good idea to mark those types of missions as such in the mission description or some other easily noticed location.