I am trying to download Amazon Unlimited music to my Lenovo Tab4. I have tried numerous songs and playlists with no success. I get the "Your Download is Starting" and each song says either "Queued" or "Downloading", but all immediately have either the X inside a circle or an exclamation point beside them. None ever download. I have uninstalled and reinstalled the Amazon Music app. I have tried saving to both the tablet internal storage and the SD card. I have re-formatted the SD card (exFAT). Sometimes the notification area shows downloading is in process and sometimes not. I can save files from the tablet, downloaded files and files from a PC to both the internal storage and the SD card. I get no error messages, it just doesn't download. I appreciate any ideas.
My tablet is running Android 8.1.0. This morning I checked and there was an update available to a later build of 8.1.0 so I downloaded and installed it. Surprise, Amazon Music downloads now work! I don't know what this update did, but I had previously tried enough different downloads and all of the usual tricks (rebooting modem/router, uninstall/reinstall, clear caches and data, etc.etc.) to be pretty sure the update was what fixed the problem.