EF Core 5 one-to-many navigation: How to get latest values in the "many" side after changing the navigation from the "one" side?

Question

EF Core 5

I have a classic setup of one-to-many navigation in EF Core code first.

One site <--> Many assets

I'll post the code just so that you see it with your own eyes :

public class Site : IAggregateRoot
{
    public Guid Id { get; private set; }

    private readonly List<Asset> _assets = new List<Asset>();
    public IReadOnlyCollection<Asset> Assets => _assets;

    public Site(Guid id) { Id = id; }
}


public class Asset : IAggregateRoot
{
    public Guid Id { get; private set; }

    public Site? Site { get; private set; }
    public Guid? SiteId { get; private set; }


    public Asset(Guid id) { Id = id; }

    public Asset(Guid id, Guid siteId) : this(id: id)
    {
        SiteId = siteId;
    }

    public void SetSite(Guid? siteId)
    {
        SiteId = siteId;
    }
}

Asset model builder :

        builder.ToTable("Asset");

        BaseModelHelper.InitBaseModel(builder);

        builder
            .HasOne(x => x.Site)
            .WithMany(x => x.Assets)
            .HasForeignKey(x => x.SiteId)
            .OnDelete(DeleteBehavior.Restrict);

Site model builder:

        builder.ToTable("Site");

        BaseModelHelper.InitBaseModel(builder);


        builder.Metadata
            .FindNavigation(nameof(Site.Assets))
            .SetPropertyAccessMode(PropertyAccessMode.Field);

It's managed with repositories, which in turn rely on Unit of Work design pattern:

public class AppDbContext : DbContext, IUnitOfWork
{
    ...
    public DbSet<Site> Sites { get; set; } = null!;
    public DbSet<Asset> Assets { get; set; } = null!;
    ...
}

then

public class SiteRepository
{
    private readonly AppDbContext _dbContext;
    public IUnitOfWork UnitOfWork => _dbContext;

    public SiteRepository(AppDbContext dbContext)
    {
        _dbContext = dbContext;
    }

    public void UnloadFromContext(Site site)
    {
        _dbContext.Entry(site).State = EntityState.Detached;
    }

    public async Task ReloadAsync(Site site)
    {
        await _dbContext.Entry(site).ReloadAsync();
    }

    public async Task<Site?> GetWithAssetsAsync(Guid id)
    {
        return await _dbContext.Sites
            .Include(x => x.Assets)
            .FirstOrDefaultAsync(x => x.Id == id);
    }


    public async Task AddAsync(Site site)
    {
        await _dbContext.Sites.AddAsync(site);
    }
}

and

public class AssetRepository : IAssetRepository
{
    private readonly AppDbContext _dbContext;
    public IUnitOfWork UnitOfWork => _dbContext;
    public AssetRepository(AppDbContext dbContext)
    {
        _dbContext = dbContext;
    }

    ...
    //The rest is similar to SiteRepository
 }
    

===================

Now I'm just trying to refresh the navigation after changes to the database. I know that the changes occur because I see it through SQL querying while the app is halted using a breakpoint. After querying, I let the app continue and do the refresh. yet site.Assets remains empty...

        var site = new Site(id);
        await sitesRepo.AddAsync(site);
        await sitesRepo.UnitOfWork.SaveChangesAsync();

then

            var assets = await assetsRepo.GetOrCreateAsync(assetIds);
            await assetsRepo.UnitOfWork.SaveChangesAsync();

At this point everything I need has been created. A site and some assets. I now want to assign some assets to the site. I do it by changing the navigation from the asset's side because it seems easier that way : I simply change asset.SiteId.

            var assetsToAdd = assets.Where(whatever condition);
            foreach (var asset in assetsToAdd)
            {
                asset.SetSite(siteId);
            }
            await assetsRepo.UnitOfWork.SaveChangesAsync();
            await sitesRepo.UnitOfWork.SaveChangesAsync();

At this point I see in the db that the site DOES have assets. All asset.SiteId are correct.

Later in the code I need to start wrking from the site's side of the navigation. Since some assets mught have been added, I need to make sure that the site.Assets navigation now contains those new assets. Therefore I try to "reload" that navigation, since EF doesn't seem to do it by itself :

            //My pitiful attempts : I've read that detaching an entity before loading it reloads the navigation...
            sitesRepo.UnloadFromContext(site); // This does _dbContext.Entry(site).State = EntityState.Detached;
            
            //await sitesRepo.ReloadAsync(site); //I tried that as an alternative...

            

            var updatedSite = await sitesRepo.GetWithAssetsAsync(siteId); //This does the Include
            
            //updatedSite is not null, I checked
            var updatedAssets = updatedSite?.Assets.ToList() ?? new List<Asset>(); //Always empty :'-(
            return updatedAssets;

I've looked at those articles but it still eludes me

Reload navigation property EF

How to refresh an Entity Framework Core DBContext?

Reload an entity and all Navigation Property Association- DbSet Entity Framework

Why won't it reload the damn navigation???

EDIT : I've detailed the repos to show how the dbContext is managed.