Input Events not forwarded to Nifty until the screen is turned off and on


I am new to jME and I’m trying to have a simple application running with nifty.

When running my application on an android device, no events are forwarded to Nifty. If I manually turn off the screen and then turn it on again, the events start getting forwarded and methods annotated with “NiftyEventSubscriber” get called.
The same application running on desktop works fine.

The same issue was described in this topic but no solution was proposed :

I guess somehow nifty doesn’t get the focus at startup but I can’t figure out why.

Any Idea ?