part of the answer you can find here:
Cosmetic breadcrumb trail
As shown in the image.
@Silvina An apparent temporary fix is to set the category as a child of another, then set it back to a parent. I've not attempted this myself, but @Ted seemed to have some success with this method.
Glad to hear that. Its a very minor issue, with no functional impact to the usability of nodebb. Just wanted to flag it out to you guys in case it is missed on version 1.0 release
Yes, set it as a child category of another, then remove the relationship to correct the issue.