In the new release of the TEI, there is, I guess, a mistake.
If one edits with ROMA the attributes of <title>, it can be seen that the attributes type and subtype are defined twice (see attached image).
This fact, I guess, produces the following error associated with ROMA:
If I create a NEW attribute of <title>, then the attribute SUBTYPE will disappear as possible attribute for <title> (!)
I guess it is due to the fact that the attribute subtype is defined twice for <title> AND one of them has no definition (see the attached image).