For me (UE 5.3.2) the problem appears only when I input a value of 0.0 in the Adjust Volume node (I wanted to mute the music with a nice lerp). Yes, it does go silent, but then if I later wish to make it loud again, it’ll be impossible, as it’s now forever broken. My only workaround was to use a small value like 0.001 instead of 0.0. Apparently a clear 0.0 breaks it for whatever reason… 
BUT here’s another weird twist: if instead of 0.001 you get greedy (like I did) and try to use something much lower (less than or equal to 0.0001), you’ll now face another problem: no, the sound will not be broken like in the 0.0 case, it will still work if you set it to a louder value later, BUT you’ll have the nasty surprise of realizing that your sound is now restarted from the beginning, instead of continuing from where it left off (which 0.001 still manages to handle properly)… 
The audio system is completely broken if you ask me…