Alright, tested the latest build - dooble-2025-02-20-qt5 - and no dice. Still the scrolling issue.
Assuming it is, indeed, the arcane timer issue - is there anything that could be done? It feels like it's something quite difficult to fix, which makes me sad, because I really love OS/2 and ArcaOS in particular, and really want to use it on a daily basis. However, without a capable browser that's a bit rough.