This is somewhat weird. I checked my scripts and the one that was updated the most recently was Niai Similar Kanji (7 days ago) and the rest was over a month ago so it seems it’s not the script change but something WK did?
From my troubleshooting it seems that “Wanikani Double-Check” is responsible (issue goes away after disabling this one)
EDIT: it seems that turning on Compatibility Mode ([Userscript]: Double-Check (Version 2.x) - #389 by staubhold) fixes the issue