Can't change the handle angle together when select 3 channels in curve editor

I have read the documentation of curve editor.but I can’t change the handle angle together when I select 3 channels on one point. It always change only one channel. Is there any why to do this or any hot keys I have miss?
by the way, I do this because I want to scale down a mesh particle use “life by time”.

please help me.

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Hello Z_SilenceMoon,

This is a known and reported issue UE-19590, and we appreciate you taking the time to report this bug. Once the issue has been addressed by our engineers, the fix will be added to the release notes for fixed issues within an upcoming full engine or hotfix release.

For now you will need to select and move these curves individually.

Let me know if you have further questions or need additional assistance.

Thank you,

Andrew Hurley

Thanks for your help,Andrew.

Was this ever addressed? I’m on 4.26 and still can’t seem to edit the RGB handles together… hoping that maybe there is some key that I’m not realizing I need to press or something.
Thanks