Scroll sensitivity in Firefox is to high

after updating to latest version scroll in Firefox is to sensitive, it’s not possible to scroll properly with mouse wheel.

Hello Wolland,
We are aware of that issue. The dev team will fix it in the future, but I cannot give you any ETA.
Now, you can change the scroll speed config if the Firefox version is 88 or newer:

if (gantt.env.isFF && parseInt(navigator.userAgent.split("Firefox/")[1])>87){
  gantt.config.wheel_scroll_sensitivity = 0.05

You can test how it works in the following snippet: