I am running Ubuntu 24.10 and I have a USB-C keyboard (Specifically a Varmilo VPE108, though I don't think that matters. I have set keyboard customizations in settings to have the keys I have control my media.
Initially, it worked fine. However, after some time and reboots, they have reverted to their initial behavior (opening the calculator, Thunderbird, etc.) Sometimes I can reset and reprogram them properly. Other times the customization menu doesn't seem to ever receive the keyboard input. For example, when I press the key to map the Calculator key to to Volume Down (pressing Calc when promtped "Enter new shortcut to change Volume Down) it opens the Calculator app and the dialog acts as if I have not pressed any keys.