This was posted as a feature request and I added my vote
In the meantime, we need a solution for our Local notebooks so we don't lose the notes
Here's my work-around
With a legacy version, I used the Save Attachments to Folder feature on my Mac
This copied the attachments (mostly pdfs) to a local OS file folder
For each note, I removed the attachment file and replaced it with a file link
I then moved the notes to an online notebook