This is related to an issue resolved earlier.
We found that if a topic's posts contained images pointing to a relative path (e.g. ![test](1.jpg), NodeBB would attempt to load them, causing them to load the entire topic again (since the url is site.com/topic/123/1.jpg).
To combat this, @baris restricted the URL so that the slug must be correct, otherwise the user is sent to 404.
For lack of a better solution, this was the approach we took, so this seems to be the reason why you're running into this issue now.
But that's what pagination is for. And if after 5000 posts the subject of the original topic has not been resolved, then it will never be.
I have a tutorial on my blog with more than 550 comments. If I had a good forum platform with a good search feature, most of the comments would not have been asked.
It would be great if there was a global setting to automatically thumbnail images in posts without user interaction.
I would really appreciate if it could be an admin setting where you could set a thumbnail-size for all uploaded images, if you click on them they will show the original image in full size.
I know there is a plugin (nodebb-plugin-image-sizer) that does resize images, but requires user knowledge.