With recent versions of Firefox, Web Access will enable clipping and switch to mouse panning, even though the platform has scrollbars. Mouse panning is only supposed to be used on platforms with non-functional scrollbars (e.g. Android).
This is because Firefox has recently enabled "overlay" scrollbars. I.e., scrollbars that hide when not used. This breaks our detection of functional scrollbars, as it is based on the fact that they occupy space.
Upstream bug report:
Firefox doesn't seem too sympathetic, so it seems we have to figure out a workaround.
Note that this currently affects Linux and Windows 11. A similar issue has been around for a while on macOS, but we had already managed that.