I'm a long time Firefox user. Often and certainly in this forum, I increase text size with a corresponding reduction in the amount of information visible at a time. I do this by using Ctrl++. ( A litttle confusing there. That's the Ctrl key and a plus key simultaneously).
I've gotten used to reading the forum this way and am generally satisfied with the way scrolling through a topic works.
Recently, I've started experimenting with Chrome (because I'm not sure what's about to happen to Firefox in version 57).
Scrolling works OK with default text size, but if I increase the size as described above, scrolling becomes very problematic. Most pushes of Page Down result in some amount of text that was just below the prior view being now just above the new view. It could be said that this amount of text is skipped.
If anybody knows how to improve this situation, I'd be happy to see any relevant information, but this is mostly FYI. I don't necessarily expect a solution here.
In response to the obvious question, I don't know if this behavior happens anywhere else. It doesn't seem to happen everywhere.
Seems to work fine on me. Chrome v62.
I have Version 62.0.3202.75 (Official Build) (64-bit), so no idea what the difference is.
For completeness, I guess I should say that, for me, this issue is persistent in Chrome. However, I've recently encountered it intermittently in Firefox. I'm so far unable to determine anything about when it does and doesn't happen in Firefox, but since I've only recently seen it at all, I'm starting to wonder if upgrading Win10 to version 1709 is somehow involved. I don't think I was using Chrome before that.
Try choosing one of the No Header themes here, click Save Changes and then reloading the page. Does it work better then?
It's possible the extra header we're adding is eating into the amount Discourse scrolls (or rather preserves when it scrolls). It seems fine to me until extreme zoom levels, or with a narrow window where the header wraps into 4 lines instead of 2, but maybe something else is at play. I do see different amounts being preserved at different zoom levels, until nothing is preserved and some parts are lost on each page-down, but only at very large zoom levels as I say.
I'm thinking about changing how we add the header as it currently has another issue with not staying in place properly when you start scrolling. Maybe both are caused by the same thing. OTOH, if you still see the same problem without the header then it may be a general issue with either Discourse or Chrome. I had a quick search of their forums and could not see anything definitely connected, but Discourse does have its own infinite scrolling implementation, and it's a difficult thing to implement, so there's certainly scope for things to go wrong.
Some of us never liked that header anyway
It's better, but not OK with Light (No Header). With plain Light, one CTRL+ (110%) starts causing problems. With Light (No Header), that seems to be OK, but another Ctrl+ (125%) causes problems.
This is all in Chrome. I haven't re-analyzed the intermittent issue in Firefox yet.