Glad that you already found the link to the OpenStudio Application. PTAC systems do not have any plant loops or air loops so you won’t see them show up in that section of the OpenStudio Application. Each PTAC is “packaged” to deliver heating + cooling to a single Zone. So you will see the full definition of each PTAC system under the “Thermal Zones” section of the OpenStudio Application. They should be in the “Zone Equipment” column of that section.
So there are no bugs here and you’ll also find that you get reasonable heating+cooling energy use when you run the simulation with the PTAC systems.