Interesting…
Additional info: the html code comes direcly from a forum post https://forum.inaturalist.org/t/mission-impossible-identify-plantae-in-africa/43528. If you right click on this page to ‘View Source’ I just copied the html from there. It is not @ mentioning you in the proper way I think? but through a hyperlink or something
Specific line likely causing the issue
<li>Your notifications through 3rd party: <a class="mention" href="/u/pisum">@pisum</a> has provided a rich <a href="https://jumear.github.io/stirfry/iNat_observations_updates.html" rel="noopener nofollow ugc">separate interface</a> to replace the dropdown. Click through the authorizations to use it.</li>
or it could be the orphaned </ol> at the end. oops