Lucki

I'm hoping the issue is just with the embeds enabled in the feed.

Sadly it's not the issue. I disabled both embed media options and it still skips a bunch of posts sometimes.

I think I was able to see what you're referring to.

I'll try to catch a jump on video later.

I still have the previous "jump" session open and continued using it for your debugging proposals:

I'm not sure the jumps I see now are the same. I now reach the bottom of the site and then the batch loads and then the jump happens over that batch. In my previously encountered jumps I was not at the bottom of the site. Please keep this in mind for the following answers:

scroll through, and see if any API requests fail when you experience one of the jumps?

No failing requests. All are green 200 and 204. Jumped posts will get the mark_as_read POST request on scrolling back up past them.

Also, what about any of the feed options? Any of those set?

I have not set them to anything specific. It looks the same except the lower two options are missing for me.

Disable media embeds in the feed and see if that is the issue

I'll give this a try, but not today anymore :)

If you scroll back up and see that some posts suddenly have crossposts listed, then that could be the cause.

I just had a jump and checked: No crossposts on them. It was in the "all" feed with "scaled" in "hybrid" mode. Here is a video of all the jumped posts: https://imgur.com/a/PgSRhud The jump was from the PlayStation post to the Formula1/Ukraine post.

What instance are you browsing when that happens? feddit.org?

Yes.

Are you using the hosted Tesseract instance, does feddit.org host an instance, or are you hosting one yourself?

Although feddit.org has an instance, I'm using my own selfhosted instance though podman.

Are you using "Compact" or "Card" view when that happens?

I'm using Hybrid. I have the feeling it happens with unseen, hence expanded, posts though.

Do you have the "Enable Embedded Media in the Feed" option enabled?

Yes.

What browser are you using?

Firefox

What platform (iOS, Android, Mac, Linux, Windows, etc)

Linux

You mentioned it seems more apparent in media heavy feeds. Can you elaborate on that? Images? YouTube and other embeds, etc?

Maybe that was a bit misleading because I set previews to always show. I do believe it has something to do with media expanding though.

Here's the settings section

What sort order? When I was testing, it was by "new" which may or may not trigger the crosspost issue as often as other sort methods

I just had a jump on the feddit.org "all" feed with "scaled" in "hybrid" mode. It happened later down though, where only unread posts were shown. It skipped exactly 20 posts. Not a single skipped post had a crosspost. Also the last seen posts before the jump have no crossposts.