Be sure to read https://yatse.tv/wiki/debug-yatse-kodi-remote to provide necessary logs and information.
Issue description: When I play a file through Kodi using MPC-HC as an external player, opening the Yatse app automatically mutes audio. This does not occur with media played inside Kodi itself, and only occurs when the yatse app is opened.
Additional information: Pressing the ‘mute’ button on Yatse remote temporarily unmutes the audio for a fraction of a second before it is immediately muted again. Changing the volume in any other manner has no effect. Reinstalling Yatse did not resolve the problem. Reinstalling Kodi and MPC-HC did not resolve the problem.