I noticed at https://commons.wikimedia.org/w/index.php?title=Commons:Monuments_database/Statistics&action=history that it didn't update for a while. https://commons.wikimedia.org/w/index.php?title=Commons:Monuments_database/Unknown_fields/Statistics&action=history did update today.
Errors recently introduced show up at https://commons.wikimedia.org/w/index.php?title=Commons%3AMonuments_database%2FUnknown_fields%2Fmonuments_nl_%28nl%29&diff=1120213424&oldid=1110494603
If I look at https://heritage.toolforge.org/api/api.php?action=search&srcountry=nl&srlang=nl&format=json&limit=500&srid=5249 , it points to https://nl.wikipedia.org/w/index.php?title=Lijst_van_rijksmonumenten_aan_de_Singel_(Amsterdam,_Noord)&oldid=67283668 so all the November 2025 edits are missing.
So looks like the harvesting completes, but the merging into the big table fails.
I believe @JeanFred did a bunch of upgrades in T409003 that might have triggered this. T409716 might be related too (not sure).