I believe this is caused by the recent pixiv html layout change that broke some other scripts too.
IIRC, the translated tags were used to be displayed under the original artists' name.
Now they are displayed to the side of it, so when either is too long, the original artist name becomes obstructed by the translated tag.
https://github.com/evazion/translate-pixiv-tags/blob/ca2434abe59dcbccb561ff9e1baf66fb045a6c0b/translate-pixiv-tags.user.js#L3367-L3390
I believe this is caused by the recent pixiv html layout change that broke some other scripts too. IIRC, the translated tags were used to be displayed under the original artists' name. Now they are displayed to the side of it, so when either is too long, the original artist name becomes obstructed by the translated tag.