Parts of the form are showing in other language, neither translation prefixes/acronyms are showing when language debug is on.The pieces of the form that have been noticed broken are (see bullet points and image):
- Form sections: the section tab title
- Items under the Related Links section of the form
- The title/label of the related list
This issue is normally user specific.
Clear instance cache, just clearing the cache once should resolve the issue and issue will not reappear.