In (at least) V11.01 FP2, when using a @formula in the input enabled section of (at least) checkbox, radio button or listbox field, it is not working.
When using a simple formula like @if(@getfield("IsAdmin")="1";@True;@False), it looks like the @true is set, however when you click on the field, you can't change (and clicked item will be gray). A text or author field for instance this is no problem and working with this formula.
When I only use @true (or @Return(@true) as formula, its working.
@if(@getfield("IsAdmin")="1";@return(@True);@False) is NOT working as well