Yet to double check if I removed Plex player from the list. I do have Plex running in my home setup. But not on the network where my music is sitting. I have a complex network setup at home, and Plex is sitting on the IoT network. I'm using something called "Promox", and running Plex in a container that's on the IoT network. Music on my Hifi is on it's own network and they don't interfere with each other.
On this IoT network I have various players around the house (Nvidia Shields) and running the Plex App. I also have PlexAmp installed on my phone (plex pass required) where I use to play music when I'm driving.
As snoopy said Plex isn't really that good as a hifi music player. However, it does an OK job streaming movies around the house, for android auto driving, or when I'm in the middle of nowhere looking for some entertainment (I don't have netflix).