During Multicam edit you cannot use sliders to increase the size of the frame.

In PP 2024 If you were doing a multicam edit and you wanted to punch into a shot you could use the slider in the effects controls to enlarge the frame. Now in 2025 and the most recent beta it freaks out. This has happened on a Mac and Windows machine.

You can still type in a value But it would be nice to be able to use the slider again