Chapters start randomly anywhere from 0% to 20% down the page list.

[Amariithynar]

Maybe it's because of how pages get loaded when you have it set to long strip (also fit width, left to right, header hidden, progress hidden, if those settings make any difference) but whenever I click into a new chapter it ends up loading such that it could be anywhere between 0% and 20% down the pagelist for the chapter. This has been an issue for some years now, but it was sporadic enough that I just dealt with it, until now where it seems to be happening at every single chapter now, it feels like.

Any ideas about why this is happening and how to stop it?

 

[HDMI1]

This, it happens on both desktop and mobile browsers. I always thought it was set to start a few pages down to skip over any credits pages that the chapter starts with.

 

[Tony_Mushah]

sporadic

This is the first time i have seen such word.

Any ideas about why this is happening

Those statements might be incorrect.
Please take this part with a big grain of salt.
When you load a chapter page, Mangadex:

• fetch the chapter metadata
• fetch title chapters metadata for next/previous to it
• fetch the actual chapter images metadata.
• fetch and then cache (on the browser) chapter images in parallel

And the last part might be issue.

So, When a chapter page is loaded on the longstrip configuration, fix me if i am wrong, it scroll directly to the first image that have been loaded (aka. fetched and cached).
Or maybe a scroll restoration issue.

Personally, Loading the images in parallel is a good idea, otherwise (loading them sequentially) loading a chapter will be taking more minutes depending on the size of each image and your internet connection speed.

It's just that the implementation of it on some reading mode may not right.
In occurence, widestrip and longstrip.

how to stop it?

Just wait for a developer to fix it.