It is tricky: Apparently it seems to depend on the terminal.
On my experience with foot terminal with xterm-256color:
mouse=“” makes the scrol work on my terminal.
But using mouse=a (see this) and setting TERM to tmux-256color make my terminal applications mouse support work properly, but neovim’s :term itself still won’t work.
So the solution for me would be setting mouse=“” when inside the term, but setting mouse=“a” TERM=tmux-256color before launching my terminal apps.