When using hime input method, mouse wheel scrolls tabs instead of text within current tab

[ckhung]

I use the hime input method on debian 12.5 bookworm + (icewm or xfce4). In the sakura window with multiple tabs, scrolling the mouse wheel results in switching among tabs, not the expected behavior of vertically scrolling text within the current tab. If I replace hime with ibus, then this problem goes away. xfce4-terminal does not have this problem. Guake/guake#2142 from the guake terminal project looks similar.

I am cross-posting this issue from the same issue in hime. My apology if this is not welcome.