the names of the mod elements do not change when exporting the mod

I will explain this in the most understandable way possible.

I have been working on the "error correction update" of my mod, I finished it and in theory, everything went well, I updated the mod, everything is fine here. The problem is that when I opened the Minecraft with my mod, some elements and blocks did not change their name.

for example:

there was an element called Rotten Dark Flesh, I changed the name to Dark Flesh, I opened the minecraft emulated by the mcreator and it seemed fine, the name changed, so I exported the mod to see if the change really worked, when the Minecraft opened, I I realized that the name had not changed, and in fact everything changed except the names.

This is serious for me, since I have some elements with poorly written names (since I'm not good at English), and obviously I can't upload a mod with names like that. I tried to rebuild the code to see if this was corrected, but no, it's still the same, I wonder if anyone knows why this happens or how to fix it, anything would be useful.