Chromecast Google TV: rotate output to display with default portrait mode

I recently bought a Waveshare display to connect my Raspberry Pi (RPI) to it for showing Home Assistant info. The display also has a second HDMI port which I would like to use to connect my Chromecast Google TV. However, the default resolution (EDID data) is 1080x1920, so by default a portrait mode display. In my RPI, I can rotate the screen to 1920x1080. But I'm still looking for a solution for rotating also the Chromecast GGTV. I already tried to install a "screenrotation" app, but nothing happened. I also tried to connect to the screen through adb and run some commands, but not the result I was hoping for (I got a message that the Chromecast did not support that resolution). Today I found on the internet an EDID emulator. Could this be a solution? These are the EDID timing parameters of the display:

Pixel Clock  H Addressable  H Blanking  V Addressable  V Blanking  H Front Porch  H Sync Width  V Front Porch  V Sync Width  H Image Size  V Image Size  H Border  V Border
141.12       1080           120         1920           40          40             20            2              5             1080          1920          0         0

Any idea how to solve my problem (if there is a solution)? Link to my display settings: https://www.waveshare.com/wiki/21.5inch_FHD_Monitor