No Drive Size Available during Restore

Using Firefox 78.0.2 (64-bit) on MacOS Catalina (10.15.5) I tried to restore from a backup to google drive but it failed. The backup was made via the Chrome browser:
Here’s the error:

However I have plenty of space in my Drive:

actually it seems that the restore partially succeeded. I have entries in my Firefox browser that were not there before I did the restore. But it still reported a failure.

When that failure happens what are the errors that appear on the console.
You can reach it here: about:devtools-toolbox?type=extension&

I Suggest to Active Dev tools at brave or chrome
sorry don’t know about firefox
Then go to MeMex Extension on Brave or chrome

3- the latest fetched files and there status.
4- the logs if something went wrong.