Hi All,
Same problem here, and the [Shift] + [Del] and/or [CMD] + [Del] don't help. I'm on two different Macs, but the same problem exists. If I highlight a keyframe in the edit widow, using the curves window, the entire clip deletes. I've tried lining the cursor up to the keyframe and deleting, hoping that this would help, and nothing.
The only thing that works is highlighting the keyframe then going up to the parameter in the Video panel and hitting the keyframe diamond.
This is a new bug for me, but have seen it throughout all of the 19beta versions.
Select the keyframe on the right..., Hit delete...

- Screenshot 2024-07-26 at 9.58.29 AM.png (118.08 KiB) Viewed 590 times
Clip is deleted, not just the keyframe

- Screenshot 2024-07-26 at 9.58.38 AM.png (208.13 KiB) Viewed 590 times
SOLUTION: Go up to the parameter in the editor, and while on the keyframe, click the diamond to delete it

- 01.png (550.42 KiB) Viewed 590 times