On 'itemid' when there is one row at 'history_log', this entry is not shown at fronted "latest data".
Generally if there is more than 1 row (for one itemid), the first row is not visible.
As you can see on pic 1.jpg there is two rows.

In the frontend, there is visible only the second one - pic 2.jpg- and only if I press "All" filter, after auto-refresh or after click "Apply" this record disappear - pic 3.jpg - not always possible to move the filter bar in that position to get 22:13 (in this case)

If you go to the "500 last value" section, both records are shown correctly - pic 4.jpg