LINQ creates a wrong _type

[ice19942335]

Why the Sanity Linq creates the wrong _type???

internal class CalendarEvent
    {
        [JsonProperty("_type")]
        internal string DocumentType => "schedule.metadata";

        [JsonProperty("_id")]
        internal string Id { get; set; }

        [JsonProperty("_lang")]
        internal string Locale { get; set; }

        internal Guid DocumentId { get; set; }

        internal DateTimeOffset? DateTime { get; set; }
    }

public async Task<CalendarEventList> GetDocumentsToBePublishedIds()
        {
            SanityDocumentSet<CalendarEvent> documentSet = SanityDataContext.DocumentSet<CalendarEvent>();

            var test = await documentSet
                .Where(calendarEvent => calendarEvent.DateTime >= DateTime.Today)
                .ToListAsync();

            var groq = documentSet
                .Where(calendarEvent => calendarEvent.DateTime >= DateTime.Today)
                .GetSanityQuery();

            return null;
        }

[ice19942335]

If I will pass in .Where(x => x...) instead of .Where(calendarEvent => calendarEvent ...) then it works, but, isn't it a bug??? As I spend a lot of time to get why it doesn't work.