Block versioning (part 2)

Hi I already read this forum post:

https://world.episerver.com/forum/developer-forum/-Episerver-75-CMS/Thread-Container/2015/5/block-versioning/

But neither the extension or listing versions work for some reason. I always get DateTime.MinValue.

I have tried...

public static class ContentExtensions
    {
        public static DateTime GetLastModified(this BlockData block)
        {
            // ReSharper disable once SuspiciousTypeConversion.Global
            return block is IChangeTrackable changeTrackable ? changeTrackable.Saved : DateTime.MinValue;
        }
}

And also tried:

var softLinks = _contentSoftLinkRepository.Load(page.ContentLink, false)
                    .Where(x => x.SoftLinkType == ReferenceType.PageLinkReference)
                    .Select(x => x.ReferencedContentLink)
                    .ToList();
                var contentLinks = softLinks.Select(_contentRepository.Get<IContent>).ToList();
                var blockDate = softLinks.OfType<BlockData>()
                    .SelectMany(block => _contentVersionRepository.List(((IContent) block).ContentLink))
                    .Select(version => version.Saved)
                    .OrderByDescending(date => date)
                    .FirstOrDefault();

Any ideas?