Something weird happend with my dock
I recently bought an used dock, didn't come with the usb-c cable but it had the power supply and the HDMI cable, I also bought a used transparent clear pocket (they came as a package)
Today I tested them, the pocket works as intended, so I loaded some cores and plugged the dock on my 50 inch screen; I used my iphone USB-C cable with the dock's power supply and most of my cartridge games ran fine, but then I tried the GB core with the DMG video mode and it came out like the first image, I quit, the checked the snes core and it was fine, came back to the GB core anda again, the first image, as you can see there is a different color on the upper left corner; I changed the video mode to GBP light (second picture) and it was fine, then returned to the DMG video mode and now it's fine; what happened? should I be worried? is the dock malfunctioning or is something with the core; on the pocket it doesn't happen something like this.
Also, the dock and the power supply got hot and I was only testing for about 20 minutes, runing cores for SNES; Genesis and arcade games, is this normal?