I should have mentioned this as well. I also got an OLED. The same adapter worked on my LCD without problems. And a friend tested the keyboard with his LCD.
But I’m a bit glad to hear that it is not only my Deck with this behavior. But also I find it annoying that I have to connect a powered dock just to use a USB drive or a keyboard.
I agree, the hot plugging of peripherals seems to work seamlessly in the BIOS. Perhaps there is a bug related to power-saving features. On my laptop, there is a configuration for USB-C behavior in the filesystem, preventing power delivery(autosuspend) when no power supply is plugged in. However, this should not be the issue currently, as the connections are functioning properly under the LCD on the same OS version. It’s possible that the problem lies with a driver issue.