Oh that… the localization way normal people use was very fucking broken when i started GT6, and since I also never liked opening separate Files to edit Language Stuffs I ended up writing code to generate Language Stuff for me. (especially with Items that have too many variants to work with)
Typically the Local Name for English is passed as a Parameter for my Items. It should be easy to reverse that change and use the vanilla System should you like to do so. Otherwise @OvermindDL1 might be able to help too though, if it is a Dev Environment Issue. ^^