Tags were unintentionally duplicated

Hi, I have about 3700 tags. And most of them are in traditional Chinese.
I usually use auto-completion to tag my documents, but sometimes I get duplicated new tags (DT create a new tag with the same name) and have to move documents to older tags. I checked the case insensitive tagging but still got duplicate tags all the time. (and I don’t think there’s Case in Chinese.)
Please help, thanks.

Are you able to reproduce this issue or do you remember what kind of action caused the duplicate tag and what you entered? To get rid of unnecessary tags you could select Tags in the sidebar, afterwards select a pair of duplicate tags in the main view and Tools > Merge Tags.

Hi, cgrunenberg:
Strange things happened.
After I removed DT3 ,reinstalled it and imported my database from the web. The problem was solved.
Before reinstallation, 2/3 of tags I tagged were duplicated.
Case closed temporarily.
If anything goes wrong again, I will report to you.

And thanks for the tip for merging tags, it helps a lot.