Aux jack losing volume

For quite some time, I've had relatively loud volume from devices plugged into my 3.5 jack in the center console. My idea of loud enough is 30 on the radio, and I've had the volume set to 30 for the 3.5 jack as well, until recently.
I've been using a ground loop isolator, as well as a cheap usb powered bluetooth adapter to listen from my phone to bluetooth. I've noticed for about 2 months now, I've had to crank the aux input to 45 to be able to hear much of anything from aux, be it over bluetooth or plugged directly into the jack or ground isolator.
Would this thread: Aux audio input fault on Gen II Prius - A Cheap Repair that works (Part 86190-53010) | PriusChat help in my case? Has anyone else run into something like this?
Thanks for reading.