EntityFrameworkConcurrency.cs

private async Task SaveChangesAsync()
{
    try
    {
        await _dbContext.SaveChangesAsync();
    }
    catch (DbUpdateConcurrencyException ex)
    {
        //adapted from: https://docs.microsoft.com/en-us/ef/core/saving/concurrency
        foreach (var entry in ex.Entries)
        {
            if (entry.Entity is Shift)
            {
                var proposedValues = entry.CurrentValues;
                var databaseValues = entry.GetDatabaseValues();

                foreach (var property in proposedValues.Properties)
                {
                    var proposedValue = proposedValues[property];
                    var databaseValue = databaseValues[property];

                    // decide which value should be written to database
                    // in the future we may need to update this if a 
                    proposedValues[property] = proposedValue;
                }

                // Refresh original values to bypass next concurrency check
                entry.OriginalValues.SetValues(databaseValues);
                await SaveChangesAsync();
            }
        }
    }
}