I have a new 2725QC (Dell) Monitor that uses USB-C connection to connect with the iMac (2019, 27 inch) through the back port but the problem is that the volume control can currently only be done from the hardware, not the software control using the Apple keyboard. What should I do in terms of writing code to do this (Swift or Obj-C)? Is there a third-party solution for Intel iMac and ARM Mac?
Dell monitor volume control issue on iMac via USB-C
It is actually S2725QC model from Dell.
Our engineering teams need to investigate this issue, as resolution may involve changes to Apple's software. Please file a bug report, include a small Xcode project and some directions that can be used to reproduce the problem, and post the Feedback number here once you do. I'll check the status next time I do a sweep of forums posts where I've suggested bug reports and post any information about changes I am able to share to this thread.
Bug Reporting: How and Why? has tips on creating your bug report.