This symptom was occurring to me because I was on a network with a Pi-Hole, had Safari's "Hide IP address from trackers" on (which I think uses the iCloud Priva

This symptom was occurring to me because I was on a network with a Pi-Hole, had Safari's "Hide IP address from trackers" on (which I think uses the iCloud Private Relay to get some resources usually delivered by CDNs that track), but the Pi-Hole was configured with the 'BLOCK_ICLOUD_PR' option on. Safari would just hand when it attempted to get those resources.