Please use the following link to download the earlier version (1.12.2) and update: Dell Latitude 5520 and Dell Precision 3560 System BIOS | Driver Details | Dell US
Received new work computer from employer a Dell Laptop. Connected my S2719H monitors to the unit and the internal speakers for the monitors worked fine and I could see them in Windows as external speakers. Ran a bios update today December 12/2021 and after restart it no longer has the option to select the monitors as external speakers I only see the laptop speakers and my work headset speaker. In sound settings as well the external monitors not long show as a device for playback.  Read some other articles with similar issues and everyone says that the monitor only has sound out through the audio jack on the back and will not play sound through the built in speakers via HDMI, which I can tell you is false, it was playing sound perfectly for over a year through the HDMI and USB-C ports. After I did a bios update all of a sudden its not an option to play sound through my built in monitor speakers.  What could be the cause of this?  Any help please. 
Latitude 5520, BIOS update, dual S2719H no sound