revert keyboard shortcuts for working with masks
Selection tool used to select all mask points with alt and add point with shift-alt, now you have to use the pen tool. why?

Thank you for filing this request.
Please update to the latest version of After Effects. As of today, 11 January 2021, the current public version is 17.5.1.
The October 2020 release of After Effects, version 17.5, did change the behavior of using the Option (macOS) or Alt (Windows) key to dynamically change the behavior of different tools. This was done to accommodate the improved 3D camera tools. In After Effects 17.5, when there are 3D layers present, holding Option/Alt while using any tool would switch to the Universal Camera Tool.
This behavior can be disabled via a new option: Preferences > 3D > “Activate Option/Alt – Left/Middle/Right mouse click for camera navigation”. This is on by default, and disabling this will restore the previous behavior of tools when there are 3D layers in your comp.
That said, the feedback we heard was that this new behavior in After Effects 17.5 was too aggressive and disruptive. So in the After Effects 17.5.1 update, we dialed back the behavior so that the Option/Alt key only activates the Universal Camera Tool in cases where there wasn’t already an alternate behavior for the tool you are using.