Is there a service disruption right now? I am having trouble getting basemaps to load online and in Pro, and some of my tools in my experience builder apps aren't working.
Some of our users noticed our maps that display the Imagery Hybrid base map were struggling to load 3/27 around 1:30PM Arizona time and 3/28 in the morning. It is a very intermittent issue. We are connecting using Esri's basemap JavaScript API.
I spotted a note on https://status.arcgis.com/ yesterday that mentioned scheduled base map maintenance for 7-9pm so that could be part of what's going on.