Well, it seems that I have solved it and I confirm the solution.
I still don't know why it started, but it seems that I had almost all the files and directories in the Documents directory in the same situation. It's not that it didn't allow me to rename the new directories that I created in that directory. It's that I couldn't rename most of them.
Curiously, this didn't happen with the files and directories inside the directories of the Documents directory.
Once I did the process of copying the entire Documents folder to the desktop, the issue of allowing me to give a name or rename the newly created directory was solved. Even so, the rest didn't.
This time it did allow me to rename them without any problem with the command line and the "mv" command, but not through the graphical interface.
Looking at the results of the "stat" command, I haven't found anything abnormal.
Even if I changed the permissions of the directories or files either through the graphical interface or by using the "chmod" command, it still wouldn't let me rename the files with the graphical interface.
I confirmed that the permissions had changed correctly with both "ls -l" and "stat".
So in the end the procedure I followed and now I notice a normal functioning in the directory is:
1.-Create a directory called "intercambio" on the Desktop.
2.-Do a "chmod 755 *" in the Documents directory through the command line.
3.-Cut all the internal content of the "Documents" directory and paste it into the "intercambio" directory.
When I tried to rename a file with the graphical interface in the "intercambio" directory, the problem persisted. That is, it still didn't allow me to rename it with the graphical interface.
4.- Cut all the internal content of the "interchange" directory and paste it into the "Documents" directory
When I tested a couple of files and directories once they had been copied back into their original "Documents" directory, I was now allowed to rename them in the graphical interface. When I tried to create a new directory in the "Documents" directory, I was now allowed to give it a name and/or rename it later in the normal way.
So I think I have now solved the problem. And I can confirm that this method works correctly.
I still don't know why or when it happened, and I don't think I'll ever find out. Nor if there may be more affected directories. But the fact is that the procedure works correctly.
I want to understand that it is very likely that something went wrong in the "box". Because the main problem was in the graphical interface and through the command line they were not given. The permissions were correct and the change of them was carried out correctly.
When I cut the "Documents" directory and pasted it directly into the "Desktop", and then did the reverse process. I solved the problem of not being able to create directories graphically and give them a name or rename them later. But I didn't solve the same problem that occurred with the rest of the files and directories within the "Documents" directory.
When I created a new directory with the graphical interface, I was now allowed to rename it, but it had strange graphical effects, the behavior was not completely normal, the renaming request appeared in a strange place and the folder was duplicated and darkened until I assigned the name to it. It was not the usual behavior. Something still did not work normally.
Through the procedure written above I confirm that for now everything works normally. And if I have any other directory that has the same problem, I can now solve it with this quick procedure.
I suppose it is something strange and there are no more affected, but just in case, I leave it written here. In case it helps anyone.
My thanks to everyone for their interest, help, and knowledge. Although I leave with the bittersweet feeling of not knowing the causes. The experience has helped me learn some new things and I take with me the satisfaction of having (I think) solved the problem.