Hello!
Thank you for contacting Walking War Robots technical support.
Please accept our most sincere apologies for all the inconvenience caused by the issue with the game sound disappearing. This issue is of the highest priority for our team at the moment and a fix is being created. Unfortunately it turned out that this client modification is quite hard and time-consuming.
However during the research of this issue a temporal cure has been found. If you are still facing this problem, we recommend you try switching your device to silent or vibration-only mode before launching WWR application. According to our information this may help decrease or totally remove the issue influence on your game experience until the global fix is ready.
Best regards, Nikita.
WWR support team.