There is a problem in my organization's web maps where information from a joined table only appears intermittently when using the identify tool. We have a polygon feature service for parcels on our GIS server that is joined to SQL data from another server by parcel number. All the data appears properly when using ArcGIS desktop, but when using our web maps or even the map viewer in ArcGIS online, the joined data does not properly appear for many parcels when identifying a feature. If I refresh the page, a different set of features does not show the joined data. I have attached pictures to show what I mean. Here is a picture with with a properly working identified parcel:
And here is a picture with empty joined data:
I am unsure how to resolve this issue. It started happening within the past few months. I would appreciate any advice, but bear in mind I am by no means an ArcGIS expert.