We have had a few issues raised about user synonyms being marked as incorrect recently. I have been looking into the issue but so far I have not been able to reproduce the problem. If anyone encounters the issue and is willing to help out by debugging the issue via a screen-sharing session then I would really appreciate the help in getting to the bottom of what is causing the problem.
If you are willing to help and can reproduce the problem fairly reliably, I am available from 9am BST most weekdays. If you can help please send an email to hello@wanikani.com and mention you are wanting to do a screen sharing session with me related to the user synonym issue and I will then be able to send a link to a screen share meeting as soon as I see this message. Alternatively we can schedule a time that would work for both of us if that helps.