When hovering over a point on a history graph, the tooltip that displays sometimes exceeds the length/width of the page. This results in behavior that is much easier to show than describe, so I recorded a video demonstrating the problem: home-assistant/frontend#16622 (comment).
There has been an open issue for this since May 2023, and it keeps going stale: Vert. or horiz. scrollbar + history-graph tooltip: dashboard blinking frontend (home-assistant/frontend#16622).