Copy Bezier pen behavior from After Effects
In AE, we can hold down the alt/option key to instantly break smooth anchor points. In other words: Dragging a control point while alt/option is down, enables separate manipulation of the control point (breaking it).
This is way more effective than selecting a separate tool. Maybe this can be added, since alt/option has no function at the momen. (and because in a suite - one would expect similar tools to work the same ;-)
Egor Chistyakov commented
Jan, it works in Illustrator the same way as is in AE. It worked like this for years. It could be a bug though... Then you need to record it and send to firstname.lastname@example.org for them to investigate at your machine.
This works as expected in my installation of illustrator 2020 and 2021; either when drawing or after a path has been drawn. holding alt (windows) and clicking on a bezier handle 'breaks' the smooth point allowing manipulation of each handle separately.
Maybe you have found a bug?