I completed the tasks of league of angels III then i went to try league of angels II.

Guys you have to use a new email to be able to play otherwise you will receive messages like this Please, keep in mind that only new players are able to complete tasks from games. We strive to provide equal chances for everyone, so we can accept screenshot only if you haven't played the game before, and that seems not to be the case here.

the first game installed was league of angels III so how can I not be a new player when I installed the app after I started League of Angels III

League of Angels and Arc have this issue. all of the other servers offer the selection to use multiple games with the same account

Two different games owned by one company, you created one account with the company, you need a new account per game. So 1 email for LoA2 and another for LoA3.
But yes Gamehag should make this clearer.

Startrek from arc and neverwinter have the same issue
The thing is that my graphics card doesn't work with star trek so I enrolled on the laptop tgen signed in and installed on the Xbox one, now I need to become gold member to play

Odd how they accepted the 1st task, maybe you just slipped through the net.
(Maybe see if you can sign up for the geforce now beta if your havin trouble running the games? you'd need a decent connection though)