For some searches, changing the Discover 'Sort' option (top-left) to 'Sort by Date (newest first)' returns incorrect/inconsistent results. An old article features above the new.
The workaround is to instead use the Publication Year filters (left-hand filter option towards the middle). Either the 'Last 5/10/25 Years' or a 'Custom Year Range' and the 'Sort by Date (newest first)' provides the correct results (eg those resources published in 2023 first).
Apologies this is a known issue that our suppliers are investigating.