No highlight for a selected entry in menus when scrolling?

[097115]

Consider this example:

dzen2 \
    -fg black \
    -w 300 \
    -h 30 \
    -l 3 \
    -p \
    -m \
    -e 'onstart=uncollapse,grabkeys,scrollhome;button4=scrollup;key_k=scrollup;button5=scrolldown;key_j=scrolldown;key_Escape=ungrabkeys,exit;button1=ungrabkeys,menuprint,exit;key_Return=ungrabkeys,menuprint,exit' <<EOF
TITLE
aaa
bbb
ccc
ddd
eee
EOF

Which produces a menu named TITLE with three entries visible at a time that can be scrolled either with a mouse-like device, or with j/k (and then selected either with the left button or with Return).

Now, if we hover a mouse over the menu, the entry below the mouse pointer will get highlighted. However, if we then start scrolling, the highlight will be gone, so it won't be possible to tell, which menu entry is currently selected (obviously, until we click on it).

Same if scrolling with keys, except no highlight will be present at all (and when pressing Return, the first visible entry will be selected[^1]).

So, am I missing some configuration here, or nothing can be done, and this is probably a bug? :)

[^1]: Which also leads to another problematic side-effect: if in this example we scroll with keyboard, then the last entry we are able to select is ccc, while entries ddd and eee are simply inaccessible.