Reported in https://forum.matomo.org/t/visitor-profile-bug/34827 and can be reproduced in demo

When I press ‘Load more visits’ button, the only thing that loads is headers of visits and info about it, but not actions. When I press then say ‘64 actions in 39 min 42s’ in loaded visits after previous press - nothing happens. Maybe this is intended? Then how I can view older actions of visitor?

Problem can be reproduced on your demo site:
https://demo.matomo.org/index.php?date=yesterday&module=Widgetize&action=iframe&visitorId=71f83188eb658d7b&idSite=62&period=day&moduleToWidgetize=Live&actionToWidgetize=getVisitorProfilePopup