Concurrency Check issue with EF Core 8 (Regression from 6)

[Ryan Kelly]

I have been working on porting an EF implementation over to EF Core, I noticed that a fairly important use case for us, Concurrency Checking, wasn't working as expected, the underlying value had not changed but it stopped returning the expected concurrency error that our application depends heavily upon.

Having dug into this I've created what I feel to be a really minimal reproduction of the issue which follows

https://github.com/rtkelly13/MySQLEFConcurrencyBug

By adapting and simplifying the current Concurrency test in the MySQL repository. Hopefully my reproduction of both the behaviour on 6 and 8 will help identify the issue.
I hadn't got far enough to copy the source and attempt to compile it myself, I managed to debug the EF Core code up to the MySQL layer using Rider

Tested on the mysql:8.0 docker image running locally.