Android - Back Button

Hi guys,
Been playing a couple of days now on Android build and it's awesome, really good job.
Couple of things I have noticed.
When the messages tab is open and the back button is pushed it crashes the game even to the point where you can't relaunch the game without first force closing it. I have tested the back button in most other scenarios and it takes you back a screen as expected so it seems it is just when the messages tab is open.
Also, when going to the security clearance screen and selecting to purchase a level 2 clearance the thanks message comes up but there is no way to return to the main menu. I had to force close the game to get back to the main menu.
Also, is it possible to stack the notifications? It is quite easy to mass loads of notifications.
Samsung Galaxy S6 running 5.1.1
Been playing a couple of days now on Android build and it's awesome, really good job.
Couple of things I have noticed.
When the messages tab is open and the back button is pushed it crashes the game even to the point where you can't relaunch the game without first force closing it. I have tested the back button in most other scenarios and it takes you back a screen as expected so it seems it is just when the messages tab is open.
Also, when going to the security clearance screen and selecting to purchase a level 2 clearance the thanks message comes up but there is no way to return to the main menu. I had to force close the game to get back to the main menu.
Also, is it possible to stack the notifications? It is quite easy to mass loads of notifications.
Samsung Galaxy S6 running 5.1.1