We are having this same issue except our services are hosted in local ArcGIS Server. We had data updated today at 6:20 AM and at 1:17 PM the downloaded data is still not updated.
Loudoun Land Use Existing Structures
The data tab shows the correct information:
The search results page shows the correct updated date but the old number of records:
Download Cache it set to automatic. I tried the manual reset button several times to no avail. The data takes seconds to download so I'm assuming it wouldn't take long to update the cache. I waited over an hour after I first clicked to update the cache.
For the two layers I'm currently having an issue with, all the data was replaced with new data, if that matters. We have other frequently downloaded data (addresses, parcels) that is typically updated 4 days a week. Those appear to be fine right now with the last update occurring 3 days ago.
(Similarly, when adding or removing a field in a layer I have to unshare and reshare with Open Data as the workaround stated above for the change to show up correctly.)
Thanks,
Sue