This feed is 27MB and the max feed size is 20MB. While I can raise the feed size limit I’d better don’t since it will lead to more resource consumption. I think you should ask site owner to limit the size of their feed. It has 400+ articles from last 1.5 months. They could limit it to 20-50 articles.
Thank you for your excellent service, I will contact the author of the website to take a look.