问MySQL/MariaDB删除长用户名的用户失败

EN

MariaDB [(none)]> SELECT Host, User FROM mysql.user;
+-----------+-------------------------+
| Host      | User                    |
+-----------+-------------------------+
| 127.0.0.1 | tenant_2SxSBywyXh3QW5L4 |
| 127.0.0.1 | tenant_4j3CWVXjgtDD2OrI |
| 127.0.0.1 | tenant_5OOBxRgjSvFehwI2 |
| 127.0.0.1 | tenant_6C3vAqBTVns8rMTT |
| 127.0.0.1 | tenant_9PVCY1Msa61u43Oh |
| 127.0.0.1 | tenant_RyFspluIGEi3Fkby |
| 127.0.0.1 | tenant_SQtfEQZmWRFfKmHy |
| 127.0.0.1 | tenant_VC8pYaJ3it1LdYK3 |
| 127.0.0.1 | tenant_Zr84h3vkLdwkqR33 |
| 127.0.0.1 | tenant_cvifD1I2Rjghjnpu |
| 127.0.0.1 | tenant_jO1tUJJokremTW5P |
| 127.0.0.1 | tenant_p6Bhzhi0OqMH4gc9 |
| 127.0.0.1 | tenant_rjyOX1NqEN6k6mk4 |
| 127.0.0.1 | tenant_xfcHjsn0mHBfURAw |
| 127.0.0.1 | test_testing_local      |
| localhost | mysql.session           |
| localhost | mysql.sys               |
| localhost | root                    |
+-----------+-------------------------+
18 rows in set (0.000 sec)

MariaDB [(none)]> DROP USER 'tenant_5OOBxRgjSvFehwI2@127.0.0.1';
ERROR 1470 (HY000): String 'tenant_5OOBxRgjSvFehwI2@127.0.0.1' is too long for user name (should be no longer than 32)
MariaDB [(none)]> DROP USER 'tenant_5OOBxRgjSvFehwI2@localhost';
ERROR 1470 (HY000): String 'tenant_5OOBxRgjSvFehwI2@localhost' is too long for user name (should be no longer than 32)