New sharing/access issues

I use Google Docs in my freelance job. They send me the magazine stories, I download to my Google Drive folder, make suggested changes, and then share the document with one or two people as Editors. Neither is a Gmail address, but this has worked for years--until this month.

Suddenly, they can no longer open the shared documents. I have had to manage access and change it to anyone with a link and then copy and paste the link into email and email back. Only emailing the link seems to work.

This is time-consuming and slows us down.

Is there a solution?