No i am afraid there is no solution, just find another stream with AC3 although the number of streams available with anything else that AAC is becoming less and less.
I am quite happy with my Q5 pro and the build in player is great, if it could somehow be used for streams as well as local material it would be nice, not sure if anybody has any pointers about this but i think it can't be done.
Alternative solution is to get an AMlogic s912 machine and dual boot libreelec on it , you get full support for everything this way. I was just testing a Vorke Z1 i have in the bedroom with libreelec and i am very close to replacing my Q5pro with the Vorke in the main TV room.
To bad the Q5pro is about double the price of Vorke Z1 , disappointing stuff really, you would expect a premium box to perform a lot better.