I am experiencing the same kind of issues with links to gdrive files. When I create a link using the button to attach from Google Drive, it creates the link in nice little box showing the file name. Immediately, I click the new link to ensure it is working, and it does. But, when I switch away and come back, the link no longer works. I get a message "Sorry, unable to open the file at this time." (using Chrome browser)
I have been conversing with Evernote support team for 8 days now, no solution yet. Work around is to get shareable link from gdrive, and paste it into note. You don't get the box, but the link does work. This does not fix older links made using the button to attach from Google Drive.
Note that these issues are occurring on the Windows Evernote app. The links all work from my android devices.