EA has a neat facility to allow the tracking of parents from whom the vertex inherits but are not on the page to be documented
somewhere in the top right hand corner of the rectangular notation.
EA also has the facility to place a glyph (depending upon the vertex, type and stereotype)
somewhere in the top right hand corner of the rectangular notation.
The observant among you may have noticed that I used the word
somewhere (italicized - for emphasis) both times.
Now, admittedly I'm using EA somewhat creatively to create new kinds of models not envisaged by UML's creators. But, I don't think that invalidates my following comments or observations.
On a diagram I have three types of vertexes.
On one type, the parent list is above the glyph, on another type it is below the glyph and for the third it is underneath the glyph (so it is obscured by the glyph).

Is it worth reporting this as a bug?

Paolo