Photos library upload to iCloud: is it stuck or just really slow?

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iMore Question

I am in the midst of uploading a very large Photos library to iCloud and am trying to determine how far along is is progressing or if it is stuck.

in Photos, I can go to Preferences=>iCloud where it says, "now uploading xx,xxx files...". However this number isn't changing and I stated the upload process a couple of days ago. (I knew from the outset, with ~50,000 photos, the process would take some time).

I've tried pressing "pause for a day" then pressing "re-enable" to see if that might jump start the process but it seems to remain at the same xx,xxx files number.

My Photos library is on an external portable USB drive, so I'm also wondering if the speed of that drive is causing the process to grind to a halt.

Was wondering if I might move the photo library back to the SSD of my MBP and start the process over? (And if I do this, will that cause gazillions of duplicates and other shenanigans in iCloud?

Thanks for your help!