Resolve remaining blocked Down downloads from PDF API #1056

The PDF API uses Down to download the files from our Explore site, which are then sent to Adobe. We had an issue with them getting stopped by Cloud Flare, so we put in logic to bypass the bot protection if the IP was one of ours. This worked most of the time. However, in the test run we did, there were 7 occasions where we received an error when trying to download.

Investigate why these errors occurred and why the IP allowlist bypasser did not work.