NAS not recognized when importing

I have a NAS system for backing up my photos.  It is a QNAP TS251, 2-bay system.  I have had it now for approx. 2 years, and it worked fine until the beginning of February.  My normal workflow when I am importing photos into lightroom classic cc, I send the main file to an internal hard drive on my desktop, and I send a copy to my NAS.  But now, when I click on "Make a second copy to:" and then choose other destination, my NAS does not show up under Network.  When I click on Network in the popup dialogue box, it just says "No items match your search".

However, my NAS does show up when I search for it with File Explorer, and I can go on there and see everything I have backed up on it.  So why isn't Lightroom Classic CC seeing it anymore?

In Lightroom have gone into Edit, Preferences, Network and tried reconnecting LR to my network, but that doesn't seem to be working.  The only thing I can think of, is that my network password has changed from what it was before, and I am not entering a correct password.  I don't recall changing it, but it is possible, I suppose.

I have rebooted my NAS several times now, and disconnected & reconnected it from the CenturyLink router.  The light indicator on the QNAS TS-251 is indicating that it is connected to my network, and as stated above, I can locate it and navigate to it using File Explorer on my PC.

Any help you can give would be much appreciated!!

Kelly