My system at home has 2 plugins:
After upgrade from 11.3-U3.2 I can only view the image jails tab, or iocage list.
At the office I have another system with 21 plugins:
Before upgrade from 11.3-U3.2 I could not list them in plugins so I suspect this release is also affected with same issue. I also cannot list them upgrade upgrade. It takes 7 seconds to get the list from iocage list.
After testing fresh install of plex on another system it does list. It would appear that at least systems upgrading from 11.3 might not list plugins after upgrade.