When clicking on "Show older messages" in the bottom of the chatter, the page would jump to the top when the additional messages are loaded. There is already a functionality in a discuss channel to stay at the previous scrolling position (related to the content) : https://github.com/odoo/odoo/blob/ffe0db0d/addons/mail/static/src/js/client_action.js#L506-L521 This fix does the same steps for the chatter. opw-692010