1950711 - Lazy-loaded images don't load when you expand a section (until you manually scroll)

Status: RESOLVED FIXED

(support.mozilla.org :: General, defect)

Description

[Daniel Holbert [:dholbert]]

STR:

1. Visit https://support.mozilla.org/en-US/kb/ai-chatbot#w_how-to-remove-the-ai-chatbot-shortcut-from-your-firefox-sidebar
2. Click the + next to How to remove the AI chatbot shortcut from your Firefox sidebar to expand that section.
3. Look at the expanded content.
4. Scroll up or down (just a little bit is all you need). (e.g. with mousewheel or keyboard arrow-buttons or dragging and dropping the scrollbar)
5. Look at the expanded content again.

ACTUAL RESULTS:
In step 3, the images in the expanded content are missing. This is most notable with the gray box in the first sentence ("choose the settings button [empty gray box]")

In step 5 after I scroll, the images have loaded (that gray box has turned into a cog icon, and there are some helpful screenshots of Firefox UI shown after each paragraph).

EXPECTED RESULTS:
The images should show up in step 3.

This reproduces in both Firefox and Chrome, so it's not a browser bug; it's SUMO apparently being dependent on manual scrolling in order to trigger lazy loading of images, even those that are in the viewport in expanded areas.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screenshot in step 3 - images are missing

Comment 3

[Daniel Holbert [:dholbert]]

Attachment: screenshot in step 5 - images have appeared

Comment 4

[Daniel Holbert [:dholbert]]

(I assume this affects all SUMO pages with similar expandable-sections-that-contain-images. The "How to remove the AI chatbot" section that I'm using as my testcase here just happens to be where I ran into this, because it's linked from https://www.mozilla.org/en-US/privacy/firefox/ which we automatically open in a tab for new Firefox installations/user-profiles, and I was testing Firefox with a fresh profile earlier today and skimmed through the privacy notice that we were showing and ran into this when clicking out from there.)

Comment 5

[Tasos Katsoulas [:tasos]]

PR https://github.com/mozilla/kitsune/pull/6530

Comment 6

[Tasos Katsoulas [:tasos]]

A fix has been deployed to prod.