Subsonic Disables Notification Audio While Playing

[flagrama]

Problem Description: While playing audio through the Android Subsonic Music Streamer app, I am unable to receive Navigation notifications/directions or notifications sounds in general. Subsonic audio ducks out but no other audio is played during the audio ducking.
Troubleshooting Steps: Attempted pausing and unpausing Subsonic while using Navigation. I get Navigation directions and other notifications only while Subsonic is paused. I glanced at the Settings and don't see any settings that immediately jumped out at me as able to solve this issue. I did not attempt to disconnect from the vehicle's bluetooth audio connection though.
Playback Application and version: Subsonic Music Streamer by Sindre Mehus
Subsonic Version: 6.0 (build a7857c) – April 30, 2016 (I'm aware I should update, but I don't think it'll solve this issue)
Server Version: jetty-6.1.x, java 1.8.0_111, Linux (50.0 MB / 86.8 MB)

It's not often I drive long distances, but it was really annoying to not be able to play music and get directions at the same time. Resorted to listening to podcasts in a different app rather than my music collection.