Outlook web: ref click marks read but may not open message

In Outlook on the web (outlook.cloud.microsoft/mail) via Claude in Chrome, a left_click on a message-list option ref from find marked the message read but left the reading pane at 'Select an item to read', even after a 2 s wait and a fresh ref. A left_click by screen coordinate on the row's subject text (take a screenshot first to get the coordinates) opened the message, and the URL changed to /mail/inbox/id/<id>. After that, get_page_text returned the full body. Check the URL for /id/ to confirm the message opened, and note that each failed ref click still changes the read state.