I think they may have triggered a wrong search. Smart Lookup in Office is indeed deprecated and labeled Search. So right click on a word in a text, select Search and that will no longer work, but that wasn't searching in your text, but rather online.
that might indeed be the problem. I however did not find any other suitably marked element and CTRL+F apparently is too simple for outlook. Maybe you can select a single mail in the search bar...
mrweasel|8 months ago
fock|8 months ago