The forward slash is a special character that LDAP normally uses for internal purposes, as a separator between certain bits of the LDAP string. That's why it gets confused if an object name suddenly contains a /

You can try to "escape" it with a \ - so replace your forward slash with a backslash-forward slash combo.

This also applies to a number of other special chars in LDAP, such as comma (,), dot (.), equal sign (=), and a few more as you yourself have mentioned.

Short of writing special code to automatically escape this character if found in the username there is no work around for your issue.  Just because other programs have written this code does not make it the proper solution.  In fact it encourages people to continue to use non-valid characters.