I tried to correct the title of Miss Scarlet & the Duke but it added the title as an "original title"

@Peter_pbn​ 

Watch the video. It's always shown on screen with the ampersand.

And since it is written that way on screen, your title correction of the original title was evidently approved. But that doesn't change the alternate titles.

@Peter_pbn​ There literally is no other on-screen alternate title. It doesn't belong. I'm not sure why that is unclear. IMDb only goes by onscreen titles when they exist.

Titles used in other sources are  accepted as alternate titles, sometimes also as display titles. Perhaps you should read the Alternate Title guidelines.

@Peter_pbn​ 

In a limited sense. There is nothing in that guide about a website referring to it with an alternate spelling. (If this is true going forward, it opens up a whole can of worms that any website anywhere with a typo can be considered an alternate title for IMDb.) Did you read the guide you linked?

The only thing close here is:

An alternative spelling of the title as used in secondary sources (only applicable to minor differences such as "7" versus "Seven" etc.)

But secondary sources seem to be DVD boxes/posters/etc., not a website (which very likely could be a typo on said website). Even if you were to be right about it being an alternate title, it should display "Miss Scarlet & the Duke" which it doesn't. It shows the alternative title at the top of the screen.

An official site is obviously a relevant secondary source. Beyond that, the guidelines even allow for unofficial, informal titles to be listed.

Even if you were to be right about it being an alternate title, it should display "Miss Scarlet & the Duke" which it doesn't. It shows the alternative title at the top of the screen.

This is because the version with "and" is still listed as the display title for several locations, including your location (or the location in your title display settings).

https://help.imdb.com/article/imdb/discover-watch/why-am-i-seeing-titles-in-a-different-language-than-before/GHEBDSCWUXN4M6Y6?ref_=helpsrall