No ability to set "max_num_recipients" in Postorius, but it's in the database

Using Postorius 1.2.1, Mailman 3.2.0, Python 3.6.5 and MariaDB 10.3.9

There is no option in the web interface to set the "max_num_recipients" setting for a list. To change it from it's default of 10 I have to go into the database and change it manually.