Serializer for ABSRotas.Routing.Entities.Models.Integration does not have a member named RuleActions

I'm making an API with mongo db, after a while of testing, I'm trying to make some calls using linq. So I'm having the following error:

Serializer for ABSRotas.Routing.Entities.Models.Integration does not have a member named RuleActions.

I think it might be something with the mapping, but this error only occurs when I try to make calls using linq.

My calls to mongo are generic, here is the query:

public async Task<IQueryable<TEntity>> Query<TEntity>(Expression<Func<TEntity, bool>> queryExpression)
            where TEntity : Entity, IAggregateRoot
{
    var database = ConnectToDatabase();
    var collection = database.GetCollection<TEntity>(GetCollectionName(typeof(TEntity)));
    var query = await collection.FindAsync(queryExpression);
    return query.ToList().AsQueryable(); // TODO: medir desempenho de query
}

My call with the repository:

private async Task<List<LineBoardingIntegrations>> GetIntegrations(List<List<LineBoarding>> lineCombinations)
{
    var possibleIntegrationsByCombination = new List<LineBoardingIntegrations>();
    var maxCount = 0;
    var minCount = 999;
    foreach (var comb in lineCombinations)
    {
        // Here my query
        var existingIntegrations = await _unitOfWork.Repository<Integration>()
                        .Query(i => i.Status && i.RuleActions.Count == comb.Count);

        existingIntegrations = GetPossibleIntegrations(existingIntegrations, ref maxCount, ref minCount, comb);

        if (existingIntegrations.Any())
        {
            possibleIntegrationsByCombination.Add(new LineBoardingIntegrations()
            {
                Integrations = existingIntegrations.ToList(),
                LineBoardings = comb,
                GeneratedCounts = new List<int>()
            });
        }
    }
}

My model:

using ABSCard.Extensions;
using ABSRotas.Common.Domain;

namespace ABSRotas.Routing.Entities.Models
{
    public class Integration : Entity, IAggregateRoot
    {
        public DateTime CreatedOn { get; private set; }
        public Guid CreatedBy { get; private set; }
        public bool Status { get; private set; }
        public string Name { get; private set; }

        private List<RuleAction> _ruleActions;
        public IReadOnlyList<RuleAction> RuleActions => _ruleActions;

        protected Integration()
        {
            _ruleActions = new List<RuleAction>();
        }

        public Integration(Guid createdBy, bool status, string name)
        {
            CreatedOn = DateTime.Now.ToBrazilianTime();
            CreatedBy = createdBy;
            Status = status;
            Name = name;
            _ruleActions = new List<RuleAction>();

            Validate();
        }
    }
}

When i change from IReadOnlyList to List it works perfectly.

The model mapping

using ABSRotas.Common.DataAccess.DatabaseFacades.MongoDb;
using MongoDB.Bson.Serialization;

namespace ABSRotas.Routing.Entities.Models
{
    public class IntegrationMapping : IMongoMappings
    {
        public void Register()
        {
            BsonClassMap.RegisterClassMap<Integration>(cm =>
            {
                cm.AutoMap();
                cm.MapField("_ruleActions").SetElementName("RuleActions");
                cm.MapCreator(i => new Integration(i.CreatedBy, i.Status, i.Name));
            });
        }
    }
}

I hope I explained correctly, if anyone has had this error and wants to help me, I will be extremely grateful!!