After repeated attempts, I was able to back up my nucleus + metadata to the 2 QNAPs on my network that previously worked without a hitch, as well as to a WD passport that is connected directly to the nucleus + by USB. However, it’s hit and miss with all these devices both via scheduled and manual backups. I’ve re-booted the nucleus + several times as well as the network as well as the QNAPs
We’re glad that things are working for you now with your backups! Please feel free to reach out if you ever have any other questions or issues. Happy listening 
Please note that there can be problems with manual backups. We discuss those issues in this article from our Help Center.
Actually, I’m waiting to hear back from noris about a fix to Build 884 and I’m now concerned about whether my manual backups are ok