Item prototypes application storage issue

If have a low-level discovery for SNMP interface discovery and stored as a template "Template_AutoDiscoverInterfaces". I've application "Interfaces" embedded into template.

I already have item prototypes set-up like ifAdminStatus.

which is correctly set-up to application "Interfaces".

Now I edit the prototype for example new history/trend values. On application I see that Interfaces is selected. I click save and return to prototype listing screen. I see that my saved item prototypes has resetted it's application to "None".

I re-enter item prototype and click again "Interfaces" and save to fix the application. It corrects the problem.

But the bug is why in the first place Zabbix GUI resets/removes application "Interfaces" as it is selected?