Describe the bug
A Medium feed presents its entries as "new" each day, though the publication and updated dates in the feed are unchanged.

To Reproduce
Steps to reproduce the behavior:

1. Add https://sghardin.medium.com/feed
2. Mark all items in that feed as read.
3. Wait until the next day
4. See the bug: Though there are no new articles on the blog, every single article on it is presented as new items.

Expected behavior

I would expect that after being marked read, the article remains read.

Screenshots
If applicable, add screenshots to help explain your problem.

Environment information (please complete the following information):

• Device: Phones and desktops
• OS: Android 13, Ubuntu 23.04 and 23.10, MacOS current
• Browser: Firefox, Chrome, Firefox for Android
• FreshRSS version: 1.21
• Database version: [e.g. Mysql 5.7]
• PHP version: PHP 7.3 (I know)
• Installation type: Softaculous

Additional context

This behavior is not exhibited by any other non-Medium feed. I haven't tried adding any other Medium feeds.