Problem loading Lightroom pictures onto NAS

I have set Preferences in the Lightroom app on my Mac to store a copy of all original images on a NAS drive on my home network, connected to the modem by Ethernet cable; it has loaded most, leaving about 5,000 to be loaded, but every time I try to load more it just loads for a few minutes then stops, not giving any reason.  I've tried this several times, and it's very time-consuming and frustrating.  On several occasions it has loaded no images at all - even when I left it to run overnight!

This problem (or a similar problem) was reported in a previous post, a while ago, with a response that "Updates for the Adobe Photography Products were officially released on 10.20.2020 that include fixes for this issue." but it's not working for me.