You might need a Google Drive guru instead. If Duplicati can restore to another system, it got the files.
Sometimes nobody knows the answer. The only thing I found when I first saw this was with OneDrive:
Where are my OneDrive backup files? (account mistake)
Thank you. So that’s two of us. To try some testing, have you tried creating files by hand on a system?
Do they show up in the other one? I am assuming you meant Google web-based UI. If not, say what UI.
If backup is significant space, did you see the space value drop on both of the two systems in Google?
Browser hard refreshes (often Control-F5) and logout-login are sometimes good generic problem fixes.
EDIT 1:
I just tested this with Google Drive personal (not business) on two Windows PCs at drive.google.com.
using Duplicati GUI Path on server of Duplicati Backups/test 2 (sometimes the slashes matter)
Clicked Yes, got Connection worked! box, folder showed up in both system browsers within seconds.
Above using Test connection button and a Storage Type of Google Drive, but I think yours was too.
What’s different between these tests (besides results)?
EDIT 2:
is one difference (you actually tried a restore), but this is just a Google Drive web UI on same account?
If Google web UI is showing differently on two systems on same account, I don’t know why that can be.