Mixer history issue

Doing a mix today and had Melodyne on a few channels. did the fixes and bounced the tracks and got rid of all the melodynes. Later, wasn’t happy so wanted to undo and get the melodynes back to re-adjust, but the history of the mixer had no record of melodyne being there.
Anyone else had this problem?

(Cubase 9.5 latest release)
Win 7 x64