I added a table comment in MySQL as follows
ALTER TABLE northwind.fornitoriCOMMENT = 'tabella fornitori';
I can retrieve the comment with the following query
SELECT TABLE_COMMENT FROM information_schema.TABLES WHERE TABLE_NAME = 'fornitori';
that shows the correct result.

Now, I want to do the same with sqlmap, and then I executed
python sqlmap.py -d "mysql://root:pwd1@localhost:3306/northwind" -D northwind -T fornitori --comments

and the output is

[11:23:54] [INFO] connection to mysql server localhost:3306 established
[11:23:54] [INFO] testing MySQL
[11:23:54] [INFO] confirming MySQL
[11:23:54] [INFO] the back-end DBMS is MySQL
back-end DBMS: MySQL >= 5.0.0
[11:23:54] [INFO] connection to mysql server localhost:3306 closed

Here, I cannot see any table comment. Is this a bug or is there something I am missing/doing wrong?