I have now completely read through this thread about how to remove your shadow mute:
Hello, fellow CubeCrafters! Through this thread, I am gonna help you to remove your shadow mute, in a simple way that works! First of all, let me introduce you to the concept of a "shadow mute": A shadow mute isn't like a regular mute, because...
www.cubecraft.net
After observation and taking action, it appears that I was indeed shadow muted, but by following this
YouTube video, which was posted in the thread above, I have managed to successfully unmute myself. I have tested it out in-game and have confirmed that other users can now see my messages on the CubeCraft server. I thank
Oreo♥ for originally posting the thread above and I also thank
Fesa for initially replying to my post and linking me to the thread, which has now helped me to fix my problem.
This issue is now resolved.