That's caused by a "temporary" fix in an underlying library, which seems was not so temporary, given that it got into the feature freeze and release of the Ubuntu LTS I use.
This means that for the whole support period of any distro that bundled the broken feature, users will find it and have to work around it, over and over.
Can you imagine if that was for a century?
I think distros should relax their policies and not only accept changes to fix security vulnerabilities (as is the case now), but also to fix promised features that shipped in a broken state. Otherwise, once some broken software ships, it stays broken for the whole lifecycle of the distro, which is bonkers.
[1]: In case anyone can provide further feedback, ideas for the author on how to fix it, or any help. https://gitlab.gnome.org/GNOME/vte/-/issues/2504