Summary

We recently updated the NuGet package to the latest version (2.20.0) and noticed that one query doesn't work anymore. After some investigation I read that LINQ3 is now enabled by default. When I change the configuration to use LINQ2, the query works fine.

How to Reproduce

This is the query that works fine with LINQ2:

public async Task<IList<Activity>> GetActivitiesAsync<TActivityObject, TId>(TId objectId, CancellationToken cancellationToken = default)
    where TActivityObject : ActivityObject<TId>
    where TId : notnull, IEquatable<TId>, new()
{
    return await _client.ActivityCollection
            .Find(x => x.Object != null && x.Object.GetType() == typeof(TActivityObject) && ((TActivityObject)x.Object).Id.Equals(objectId))
            .SortByDescending(x => x.CreatedAt)
            .ToListAsync(cancellationToken);
}

With LINQ3 we get this exception:

MongoDB.Driver.Linq.ExpressionNotSupportedException : Expression not supported: x.Object.GetType()

I tried to use the "is" operator instead, but it also works only with LINQ2. With LINQ3 I get this exception:

System.Reflection.AmbiguousMatchException : Ambiguous match found.