This is an old bug too,but I just thought about talking about this bug today.
That’s how to reproduce the bug:
open and read a few articles
pick up an article to use the trainer tool
open the trainer tool
mark an word,tag or author as liked or disliked (I’m not sure about it,but maybe even you don’t use the trainer,if you just open it,the bug will happen too)
try swiping again to read the next unread article
Then you will see that,because the trainer tool was used,the next article won’t load anything,you can’t know what feed is,what is the article title,neither read the article content,the screen will be 100% white if you have the white theme or a 100% black if you are using the black/dark theme.
When it happens the article doesn’t load at all but it’s automatically marked as read,so if you go back to the articles list,you will see that the feed is marked as read. I’m not sure about what I’m going to say now,but sometimes you can’t even see the articles list,so you don’t know what article title and from what feed was the article that was automatically marked as read,when it happens I need to open the “last read articles” to find and see what as the article that was marked as read and that I missed because of this bug.