Hi DaveR31,
Welcome to Microsoft Q&A forum. I'm happy to help.
The slow importing issue on Adobe products has been reported by many users, not only on Windows but also on other operating systems. It seems there's no clear reason or resolution at this moment.
Regarding your information that the issue is gone if you use another user account, it could be Adobe Lightroom cache causing the issue. You may navigate to Adobe Lightroom settings to clear its cache.
You may also check that your currently account has any external link / shortcut (example: SMB shortcut, network drive, network shortcut, etc.) that was dead. Dead network shortcut may take very long before timeout and affect lots of basic function.
If above suggestion cannot help, switching to another account is necessary.
I hope that above information is helpful to you.
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