What is ACE?
ACE (Audio Capture Engine) is used in apps made by Rogue Amoeba to enable Mac's to redirect the audio signal output and allow it to be manipulated. Their Airfoil app will grab the audio and send it out via Airplay. I rarely use it, but on occasion I run it to send audio from the Music app in Catalina to my Apple TV to play over my stereo. The ACE component was updated I think 2 days ago. I will try uninstalling the app to see if it has any impact on this issue. I have sent a tech support inquiry about this to Rogue Amoeba but have not received a response yet.
From the Rogue Amoeba Website:
The Audio Capture Engine (ACE) framework provides Mac apps with the ability to capture audio from specific running applications, as well as all audio currently being produced by the system. ACE can be used to provide audio to enhance screen recording, VNC/remote access, game streaming, and much more.
ACE provides an API for applications to create virtual CoreAudio capture devices, which then pull in the desired audio. For example, ACE can be used to programmatically create a capture device pulling audio from a running instance of VLC. Any audio that VLC produces will show up as audio input from the virtual capture device. The audio can then be read and processed by your application, using entirely standard CoreAudio APIs.
ACE can be integrated into an existing application in a matter of hours. It's provided in two parts: A C library that applications integrate to communicate with ACE, and a CoreAudio server plugin to be installed on the user's computer. Functions are provided for installing/uninstalling the server plugin, as well as creating virtual capture devices.