To share with the community some things learned from a private support ticket -- There's currently a defect in the logic where if no packages were downloaded/uploaded to a debian type feed, the in-memory cache is never started. This leads to very long runtimes when running apt update since the response times for the /Release and /InRelease endpoints (from our experience) are at best 1 minute, at worst 10 minutes.
The workaround support gave was to manually download a package via http before attempting to use apt. From our experience, this doesn't persist overnight, so it would basically need done daily and truly is counterintuitive to having a package manager like apt.