Automapper - Map fails after profile is added

Question

I am using mapping by convention and have issues when adding profile to the configuration. Consider configuration below. I am using AutoFac to resolve profiles in CoreMapper and the profiles are correctly injected.

Mapping configuration

public CoreMapper(IEnumerable<Profile> profiles)
{
    MapperConfiguration = new MapperConfiguration(cfg =>
    {
        cfg.CreateMissingTypeMaps = true;
        cfg.AllowNullCollections = true;
        cfg.AllowNullDestinationValues = true;
        cfg.ForAllMaps((mapType, mapperExpression) =>
        {
            mapperExpression.PreserveReferences();
            mapperExpression.MaxDepth(10);
        });
        cfg.IgnoreUnmapped();
        foreach (var profile in profiles)
        {
            cfg.AddProfile(profile);
        }
        cfg.CreateMap<string, string>().ConvertUsing(str => string.IsNullOrEmpty(str) ? null : str);
    });
    Mapper = MapperConfiguration.CreateMapper();
}

IgnoreUnmapped is as follows:

private static void IgnoreUnmappedProps(TypeMap map, IMappingExpression expression)
{
    foreach(var propName in map.GetUnmappedPropertyNames())
    {
        if (map.SourceType.GetProperty(propName) != null)
            expression.ForSourceMember(propName, opt => opt.Ignore());
        if (map.DestinationType.GetProperty(propName) != null)
            expression.ForMember(propName, opt => opt.Ignore());
    }
}

public static void IgnoreUnmapped(this IProfileExpression profile)
{
    profile.ForAllMaps(IgnoreUnmappedProps);
}

In my code I have a generic class implementation with the line like this:

mapper.Map<TPoco>(entity);

Note: mapper is an instance of CoreMapper from above. where TPoco is POCO model defined like:

public class ModelPoco : IModel {
    // props
}

and entity is database entity model.

The mapping works fine. The result of mapper.Map< TPoco>(entity) is correct.

I then proceed and add a profile for a specific map that is not at all related to the ModelPoco being mapped before.

The profile being added:

public class  RepositoryLayerProfile : AutoMapper.Profile {
    public RepositoryLayerProfile() {
        CreateMap<SomeOtherEntity, ISomeOtherModelInterface>();
    }
}

Version: 6.2.2

Expected behavior

Mapping of ModelEntity to ModelPoco should happen normally.

Actual behavior

The mapping breaks with the message: Unable to cast object of type 'Proxy< IModel>' to type 'ModelPoco'. on line mapper.Map(entity);

I am not sure why does it create Proxy class for IModel interface and then tries to cast to concrete implementation? I explicitly set that I want to map entity to a concrete implementation.

If I remove CreateMap from the profile it works fine, but the first time I define CreateMap in the said profile, it breaks. It seems to me like it forgets about the configuration for some reason even tho it has nothing to do with it.