TTS voices have a problem all the time. I don't know if it's an application problem or if the problem occurs in this software version. The increase tts voices switch from Google doesn't work, if it doesn't work then you can hear the tts voices quietly in the Sygic application. The problem is complex, the voices download automatically and if they don't work I have to download the application from the store, uninstall the updates and then it's fine but only until I turn off the radio. If I turn on the radio the next day the tts voices are quiet, I have to go to Android settings, click the increase tts voices switch to off, turn it on again and then the voices can be heard normally. If I used the Sygic application every day I would have to turn the increase tts voices volume switch off and on every time, otherwise they would be quiet. Previously everything worked, if you didn't download the tts voices application from google from the store, set it once, the option increased the volume of tts voices worked, the switch worked all the time. In this version of the software, you can't get a compromise. I tried to record a video showing this situation, but after opening the recording you cannot hear the effect that occurs. If the TTS volume boost switch is not working, it means that your system settings do not increase the volume enough to compensate for the fact that the switch may be disabled. If the system volume was louder, the option to increase tts volume in the Google app may be disabled. The problem occurs in dudu7. 
