Just started having an issue where basemaps will not load in ArcGIS Pro 3.4.0 (and other versions) when active portal is set to our own Enterprise 11.1 Portal. Also, when in Enterprise basemaps other than Bing Maps will not load and give the error shown in first screenshot. 2nd Screenshot is from Pro.
Esri Service status showing all working normally at LINK: https://status.arcgis.com/#

