Published a feature service with 6 sublayers to ArcGIS Online from ArcGIS Pro. Added the feature service to a web map with no issues. Saved and closed the web map, then when I went back into it an error popped up "Unable to establish a secure HTTPS connection to the layer. The layer, *********, cannot be added to the map." (naming one of the sublayers from the feature service I just published). Also, the web map now appears empty even though all of the other layers from the feature service don't have an error notification (!) next to them. Everything appears fine in the Data/Visualization tabs on the details pages.
Since this layer was added at the same time as the rest, I'm not sure how to tackle dealing with it. Has anyone had the same issue or know the source of the problem?