Efcore: Index.IsUnique error with ChangingAndChangedNotifications TrackingStrategy

[Samoulou]

It seems that with the ChangingAndChangedNotifications tracking strategy when trying to delete an entity that has one of its property set as index.IsUnique, generate a tracking error

Steps to reproduce

I reproduce the case in this console app.
https://github.com/Samoulou/indexUniqueTrackingError

When launching the console app, I just create the DB and delete the concerned entity, after 5 seconds the error should be throw.

NB: the problem occurs when updating the index property too

Further technical details

EF Core version: not working with our project in 2.2.6 and with my console app in 3.0.0
Target framework: .NET Core 2.2.6, 3.0.0
Operating system: Windows 10
IDE: Visual Studio 2019 16.3.1

[ajcvickers]

@Samoulou Thanks for filing this. I have confirmed we are able to reproduce and we will discuss in our next triage meeting.