Main menu scrolling broken in 6.2.9

Distribution

Fedora 40, with a t2 version

Package version

Cinnamon 6.2.9

Graphics hardware in use

Intel Corporation CoffeeLake-H GT2 [UHD Graphics 630]

Frequency

Always

Bug description

This seems to be a regression.

Issue 108 covered the same issue a decade ago, and it was apparently fixed then.

Steps to reproduce

Configure the main menu, to "enable autoscrolling in application list.

Open the main menu.

Attempt to scroll.

Expected behavior

1. It used to be possible to autoscroll the main menu down by hovering the mouse at the botton of each list. It's now practically impossible-- I have to hit just the right spot, for it to slowly start crawling down, and it keeps stopping, and I keep having to find where that spot has moved. It is still possible to autoscroll the main menu up by hovering the mouse at the top of each list.
2. It is not possible to widen the scrollbars in the main menu, they ignore the settings under Themes.
3. If your mouse has enough buttons, it is still possible to work around this by using xinput to set a button as a scroll button.

Additional information

No response

Start by reproducing the issue in Cinnamon 6.2.9 with main-menu autoscrolling enabled, then trace the main menu's application-list scrolling behavior. Check both bottom-edge autoscrolling and the menu scrollbar response to theme settings. Done means scrolling works reliably in both directions and the scrollbar can be widened through Themes.