Plugins » Katello

After lerning that "Synced Content" is the new default method for installation media, I tried switching a test system from "All Media" to "Synced Content".
After switching the radio button and selecting the new medium from the synced content dropdown, on submit Foreman UI errored out and showed me a reset host form with "Media Selection" reset to "All Media" and "Media" reset to a blank entry. The error message in the UI is:
must belong to host's operating system and Org/Library/Red_Hat_Server/Red_Hat_Enterprise_Linux_7_Server_Kickstart_x86_64_7_4 does not belong to RedHat 7.6 operating system
next to the Media dropdown.

Error message from production.log on save:
[W|app|8db43] Not queueing Host::Managed: ["Medium must belong to host's operating system"]
[W|app|8db43] Not queueing Host::Managed: ["Medium must belong to host's operating system"]
[W|app|8db43] Not queueing Host::Managed: ["Medium must belong to host's operating system"]
[W|app|8db43] Not queueing Discovery reboot: Medium must belong to host's operating system and Medium Org/Library/Red_Hat_Server/Red_Hat_Enterprise_Linux_7_Server_Kickstart_x86_64_7_4 does not belong to RedHat 7.6 opera
ting system
2019-02-04T15:03:28 [E|app|8db43] Failed to save: Medium must belong to host's operating system, Medium Org/Library/Red_Hat_Server/Red_Hat_Enterprise_Linux_7_Server_Kickstart_x86_64_7_4 does not belong to RedHat 7.6 operating system

I then turned to my hostgroups, since these are the only other place where OS gets defined to my knowledge.
When directly editing the hostgroup of my test host, I encountered a similar error where I could not switch the hostgroups settings to "Synced Media" (the radio button is grayed out) until I either:
a) set the parent hostgroup to use "Synced Media" first or
b) switched "architecture" from "Inherit Parent(x86_64)" to "x86_64" in the nested hostgroup.
Each of these steps led to the same result, being able to set the nested hostgroup to use Synced Media and afterwards being able to switch my host to that, too.

Expected Result:
Beeing able to set/override "Media Selection" and the boot medium independently from the settings in (parent)hostgroups.