Virtualbox: Touchpad scroll not working

Manjaro host (kernel 5.7.15.1), virtualbox 6.1.12, Manjaro guest (kernel 5.7.15.1)
(Same problem goes for Kali guest)

Two-finger scroll on the host works fine. But for the guest OSes, scrolling is mostly dead. Once in a while it’s able to do some scrolling, but it’s more like acting as PgDn once every 20 attempts to scroll. It’s basically not usable.

I’ve read that some has solved this by downgrading to Virtualbox 5.1. I’d prefer another way to solve this.
Others has solved it by setting QT_XCB_NO_XI2=1
I might be doing it wrong, but it doesn’t work for me.

Any other ideas how to activate scroll in the guests?