Default audio source never the CalDigit TS3 Plus (MBP 16" 2019 w/ macOS 11.4)

Hi folks, got an interesting one. I have a Late 2019 MacBook Pro 16" and I'm using a CalDigit TS3 Plus with powered speakers plugged in to the audio port (not the optical one). I also am using a Dell U2719DC monitor via DisplayPort.

The issue I have is that I can no longer set the CalDigit Thunderbolt 3 Audio: Speaker as the default audio source for Output or "Play sound effects through". In the past I was able to plug the speakers in to the monitor (and with Loopback from Rogue Amoeba) I was able to use that as an audio source. For some reason I can't do that anymore so I decided to have the speakers plugged in to the TS3 Plus instead. However the default audio source always was set to the Dell monitor.

I have tried rebooting, repairing permissions, zapping the NVRAM, PRAM, SMC all of that. I even went as far as to delete the following files from /Library/Preferences/Audio:

com.apple.audio.DeviceSettings.plist

com.apple.audio.SystemSettings.plist

Following the instructions from the CalDigit site I then selected what I wanted to use as default right after which is the CalDigit dock, but prior to rebooting I selected the MacBook Pro Speakers for both Output and Play sound effects through. When I rebooted, it no longer defaults to the monitor thankfully, but it does default to the MacBook Pro speakers, but I wanted to default to the TS3 Plus.

It just won't. I have to manually set it to that every time I log in to my Mac. Would love any help or advice on this before I consider deleting my profile and starting fresh which will be painstaking to do but if it's to be it's to be.