Recently, when I’m reading various posts on these forums I’ve noticed a very irritating phenomenon: from time to time the page jumps up or down - I mean, it scrolls on its own quite a lot. I’m not interacting with my browser in any way when this happens and then I lose the spot on the screen where I was reading and I have to start looking where it is - and it’s usually somewhere up or down the screen. Maybe it has something to do with the new type of ads that appear between posts - maybe it is caused by an ad that is added to the page somewhere outside the visible page area, which causes the scroll jump?
@mrlagmer, IIRC, we encountered something like this a while ago and it was related to the ad height not being reserved with CSS before it loads the ad causing a screen/content jump.
I too have experienced some page position jumping. A problem for me is because it happens “from time to time” and I have not yet been able to pin down the exact cause. Another problem is that the “jumping” is different amounts, some times only a little, other times several posts.
So far my fuzzy observations are:
If I “fat-finger” touch over the post scroller at the right of the page the page will scroll to the post that corresponds to where I unintentionally touched the navigation scroller. I consider this to my own clumsiness and not a bug or UX problem.
At times I open various modals. It seems that when I interact with the modal, sometimes but not always, the touch event propagates to the scroller beneath it. Because this is both inconsistent and an edge case I have not looked into it very deeply and have accepted as a relatively minor annoyance. But it is an annoyance just the same.
Other times the page jump is only a few pixels. I think it happens either when a post datetime changes or if a post receives a Like. i.e. a height changes to adapt to the different content.
Then there are times when the page position jumps several pixels. I’m thinking it has to do with the when the advertisement in the post stream switches out to an advertisement with a different height.
I’ve noticed this and I think this is the main problem. The ads have very different aspect ratios and heights - I’ve just seen a rectangular ad switch to a landscape one and all the content below the ad moved. There would need to be a maximum possible ad height space reserved straight away, I think. The jumps I’ve noticed were often much more than a few pixels - maybe about 5 to 10 lines of text - enough to lose the reading spot.
Often this happened when the ad was not visible - somewhere higher up the page, which makes me wonder what’s the point of an ad if it is “shown” outside visible area?
That certainly contributes to the difficulty of troubleshooting. I have yet to figure out a way to see changes that occur above the fold while I’m reading below the fold. (maybe split windows?)
I’m not that knowledgeable as to how this could be corrected with CSS. i.e. responsive width and fixed height. Letter-boxing?