It may happen that the name of a street you know well is not correctly written on a Bing Maps site or in the Microsoft Maps app.
The displayed map is the same if you are on the Maps app or in the Bing Maps  site  and it should be also the same in the HERE site, being the cartography, used by all, the Here one (once the Navteq one).
… but it seems to be not so!

Just today I found an error in the spelling of a street and I notice that it is wrong in both Maps app and Bing Maps  site, while it is correct in  HERE site maps … even though in all of them it is mentioned Here 2018 as the owner of the cartography!!
Therefore, it seems that at least there is no synchronization of the latest version that Here has and that Microsoft is using.

Wrong street name in Maps app

Wrong street name in Bing Maps site

Correct street name in Here site

… and that’s really strange, being the cartography the same (and possibly updated!)!!

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But what to do, if you want to report an error you discovered on a map?

The Maps app makes reporting a wrong detail on the map very easy. You have to click on the Suggest modification (IT:  Suggerisci una modifica) button, at the bottom right, and then choose The map is not accurate (IT: La mappa non è accurata).

Suggest modification -> The map is not accurate (IT: Suggerisci una modifica ->La mappa non è accurata)

A popup window will appear asking you to move the map in order to have the grey circle where there is the error you want to report: doing so, on the popup window you will read the name of the street where that circle is located after moving the map.

You are asked to move the map in order to have the grey circle where there is the error you want to report

You can detail what is wrong or missing and then send that report.

Detail what it is wrong or missing

After sending that report, you are thanked

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To send the report from the Bing Maps site is not so evident … and I did not find it at first!
What you should try is to write feedback that anyway is generic, not specific to a map error report.

Feedback menu item available in the Bing Maps site (1)

Feedback menu item available in the Bing Maps site: too generic one!! (2)

Instead, what you have to do is to look at the top left menu and make the appropriate choices:

Other -> Comments and suggestions -> Report a problem on the map

See also the following post: How to report errors you may find in Google Maps