system fields greyed out in search screen

Scenario:
Simple project with just 2 (custom) issue types and a field configuration scheme with only the Default entry (i.e. both issue types associated with the same field configuration).
We assume also a user who has access only to this project.
Opening basic searching -> More Criteria and searching for "Component", the (system) field does appear but it cannot be selected (it is greyed out) and an exclamation mark appears next to it.
According to the documentation:
Why is there a red exclamation mark in my field?
Some field values are only valid for a particular project/issue type context. For example, you may have configured a project to use a status In QA Review in its workflow. If you select this project and status in your search, then change the search to filter for a project that doesn't use n QA Review, the status will be invalid and ignored in the search.
If I also select explicitly the project name in the search criteria, then Component does appear and can be selected.
The question is why is it necessary to select also the project name in this case? The above reasoning does not apply.
Please note also that if I switch to Advanced Search and just type Component = xxx, it does work fine.
I believe this is a bug. Could you please try to reproduce it?

PS. The above problem happens also with other system fileds, such as Fix Version for example which also appears greyed out.

Thanks,
Ioannis