I see the predicament. Nasty job to generalize that problem 🙂
Strtolower solves 100% of issues.
Default min size is 3, must be bigger than that, but if it's less than that, an alert after saved will be better.
Please monitor gh#2205
@main -- What tag are you trying to add? It works fine here, and it only didn't work when the tag character was set too high and you were trying to add a two character tag.
Try decreasing the minimum tag size to 1 character.
@julian I just tested "单" can't work too. I'm not clear which character you use work and why the tag must be 1 character?
@main -- What I mean is, your NodeBB is probably set up with a "minimum" tag size. If you try to insert a tag with fewer characters than that set size, NodeBB is instructed to ignore it.
Try to reduce that setting.
@julian Thanks, the default min size of tag is 3, so that's the problem.