Help! Emby Server is stuck in "Ready to Transfer" to my Android phone

I've been using Emby Server (4.0.1.0) on a PC (Windows 10 Pro 1809) and Emby for Android Mobile (3.0.33) on two Samsung 9+ (Android 8.0?) phones successfully for many months. I recently upgraded both phones to Android 9.0. Now, one phone works fine. The other phone cannot download recordings. The "Download & Sync" tab on the server shows "Queued", "Converting" then "Ready to Transfer", but never progresses to "Transferring" or "Downloaded". There are no log files on either phone, but the

I have to agree with the "timing" related thing to a degree. Here has been my experience with this issue. 1. This issue happens whether I try and download on my local network, or externally. For example if I am connected to Emby through my reverse proxy and a download is "Ready to Transfer" I can take a totally different device connected to my LAN and try to download the same thing and that, too, "ready to transfer". I've even gone as far as setting up a wireshark tunnel to my LAN on