ArcGIS Online Error message: Unable to load https://utility.arcgis.com/usrvcs/servers.... Status 429

[MDB_GIS]

I am getting the message under very strange circumstances. I have a web map that is using a feature service from ourportal (passed through to arcgis online using the service url with credentials stored in it). This map is used for our field crews to collect data. When you first open the map, all the features show up as they should and everything looks great. However, if you zoom in fairly close (~1:1000), they all disappear and never come back. If you then refresh the page, this is what pops up: 

You then have to completely close the map and clear the browser cache to clear the error message. Anyone have any idea what might be causing this issue?

Edit: Here is a screenshot of the console log from google chrome.