Flashcard syncing bug

So I use remnote flashcard feature a lot. To make things easier, I’ve created tags and subtags in hierarchy so I can browse and choose the tag I want to study.
The problem is even though I’ve carefully created and tag the rem accordingly, they won’t show up as tagged on rem, they’ll only show up as “everything”. Sometimes the tag work, sometimes they don’t. I’ve deleted the tag and retagged with the same exact thing and it works sometimes.
I think there’s an issue with writing tags to rem on database and unable to retrieve/read the tags?