I opened up Arc Pro this morning and attempted to add a hosted feature layer from my AGOL content, and was presented with Server Login prompt. I tried entering my AGOL credentials, and received an authentication error. Tried with numerous other feature layers, all of which I am the owner. I was even able to successfully publish a new layer, and get the same error when trying to add it to a map in Pro after publishing. I am only able to add layers that are shared publicly (everyone). Sharing to owner, organization, groups, etc. gives me the error message. Access from web maps in AGOL is working as expected.
The weird thing is that I've got another machine with the same version of ArcPro, and everything works fine on that machine (logged into the same AGOL account). I can add layers to ArcPro as expected.
This issue is brand new, and everything was working fine last week. I updated to ArcPro 3.0 on both machines about a week ago, but no issues until today.
Opened a case with ESRI support already, but they didn't have a solution off the bat. Any ideas would be greatly appreciated!
UPDATE 8/1/2022: Issue seems to have resolved on its own.. No changes on my end, and ESRI claims no changes on their end to fix the error. Clicked and dragged a hosted layer from catalog into Arc Pro Map this morning, and it added without issue. This was an Arc Pro session that was left open over the weekend, so no restart of application or computer, etc. It just started working again...
I should mention that ESRI ArcGIS Pro Desktop Support team passed me off to ArcGIS Online Support team. Both support teams were stumped on the issue, after a few days of troubleshooting. Esri Case #03112677