After a lot of troubleshooting I've identified the problem -  This BIOS update has somehow introduced an issue with 16 bit 48000 Hz sound format - it causes whatever device is using it to fault over and over again and seemingly locks out every other USB device. If you run into this problem do the following:
Hi, I'm running the following: I run 3 monitors, a wireless KB/M combo, and Jabra Evolve 75 headphones connected via USB dongle. Yesterday, against my better judgment, I allowed dell support assist to install the latest BIOS update (1.9.1) - normally I don't, but the previous BIOS update actually made the docking station work properly with multiple monitors whereas before I always had finnicky issues. After installing the update, I noticed that my headphones were constantly repeating "headphones connected, headphones disconnected, headphones connected, headphones disconnected..." and that my wireless KB/M werent working. After troubleshooting, I realized that everything works fine until the device tries to output any sound (system sounds, youtube, spotify, etc) at which point the USB dongle enters an endless loop of disconnecting and reconnecting while simultaneously killing any other USB devices connected. Also, if I remove the docking station while this is happening I get an instant bluescreen. Everything works fine as long as that USB dongle isnt plugged in, I can use BT sound (havent tried other usb headphones though), but that kills half the functionality of these headphones and is not a compromise I'm willing to make. I've verified that everything works as intended using my personal computer - no issues whatsoever with the dongle and headphones and multiple USB devices. For troubleshooting I've tried the following: At this point I'm at a loss. In my many years troubleshooting various issues (I've owned many dells, I'm basically a certified troubleshooter now) I've never seen anything like it. The device was plugged into the docking station during the update so I'm assuming that is the cause of the issue, though in 2022 I don't know why. Any assistance is appreciated - otherwise this will be the second 5760 I've had to return in 4 months. (first one had a faulty SSD out of the box)
Latest BIOS Broke my USB