The activity timeline quick expand/collapse option on click of the activity header used to expand and collapse the activity record prior to the 2022 Release Wave 2 updates being applied. This functionality has now been replaced by "View More" and "View Less" hyperlinks in the footer of the activity record. I cannot find anything relating to this feature change in the release plan.
I wonder if anyone else has faced the same issue, which I would classify as a step backwards in activity timeline usability. Many of our users are complaining they now have to scroll to the bottom of very lengthy emails to locate the "View Less" action link, in order to collapse the email in the timeline. I don't understand how this can be considered an improvement.