Selection changed event behaviour changed since 148?

Hello community,

I recently noticed that Firefox 148 changed the behaviour of selection changed events. I don’t know if this is a bug or made with intention.

Steps to reproduce

Install version 0.6.0 of my Addon FineFind in Firefox 147.0.3 and start searching for some phrases. No matter whether a result is inside the viewport or a few mouse scrolls away, when Firefox adds the green highlighter to a result, a green ring animation should appear.

Install version 0.6.0 of FineFind in Firefox 148.0b12 (Firefox Developer Edition). As long as a result is inside the viewport, everything works as in 147.0.3. However, when a result is outside the viewport and Firefox jumps to its position, the green ring animation does not appear.

Why is this happening?