Hi,
We apologize for the inconvenience caused to you.
However @rgonig2 has opened a ticket with us highlighting this issue to us.
We made a test installation of the old version i.e v1.10.4 and had LDAP plugin installed and then upgraded the installation to v1.11 via Softaculous itself and the plugin post upgrade was listed properly.
We request all users on this thread, if they have any issues with the installation/upgrade made via Softaculous to open a ticket with us so that we can check this for you.
https://www.softaculous.com/support/
We request for ticket because we may need some more details like the installation details OR the control panel login in order to check this further for you.
Also we follow the standard upgrade procedure which is given by the OSTicket itself.
Thank you.