Waveshare 4 Inch HDMI Screen not working [HELP]

I'm facing an issue with my OKDO Rock Pi4C+ board setup and I'm hoping some of the knowledgeable folks here might be able to offer some guidance.

A bit of context: I have a 7 inch HDMI touch screen that's been working perfectly fine with my Rock Pi4C+ system. Recently, I decided to purchase a Waveshare 4 inch TFT LCD touch screen. (https://www.waveshare.com/wiki/4inch_HDMI_LCD) Unfortunately, this new screen is not displaying anything when connected. There are also no errors popping up, just a blank screen.

In an effort to resolve the issue, I've tried using the LCD4 show package (https://github.com/waveshare/LCD-show/blob/master/LCD4-show), which is designed to support this screen model. Despite this, the screen still doesn't display anything. I even attempted to follow an installation manual for a Waveshare 3.5 inch screen (https://wiki.radxa.com/Rockpi4/hardware/display), thinking the procedures might be similar. However, this approach not only failed to get the 4 inch screen working, but it also caused an unexpected error on the 7 inch screen when I plugged it back in.

Just to clarify, I'm running the Debian 11 distribution provided by Radxa on my OKDO Rock Pi4C+, and I'm using the official power supply. I've also double-checked the screen connection and everything seems to be in order.

Here are my setup details:

• Board: OKDO Rock Pi4C+
• OS: Debian 11 (Radxa's distribution)
• Screens: 7 inch HDMI touch screen (works), Waveshare 4 inch TFT LCD touch screen (doesn't work)
• Power Supply: Official
• Troubleshooting Steps Attempted: LCD4 show package, Waveshare 3.5 inch screen installation manual

If anyone has experienced a similar issue, or has any tips, I'd be extremely grateful for your advice.