text-to-speech Engine

I'm using Free Navigator on my samsung S6 Lite 10.1 Tablet,. Since newest Update of MapFactor Navigator I can only select Samsung-Text-To-Speech engine and not anymore Google text-to-speech or my installed one (Acapela TTS). Even I have set this engine as default in Android, MapFactor only gives me Semsung-Text-To-Speech in the list to select. It seems that software just lets me select first engine in android list and not the default one of TTS-Engines available. In other apps it works fine. Any solution?