I am having same problem as user Ruukoto. Open an email in ProtonMail, click the hyperlink, try to delete the mail. It log me out. When I disable this extension, all is fine. It wasted like 1.5 hour of my time and caused major discomfort. This extension is not updated apparently.

Please correct me if I'm wrong but don't cross-site cookie isolation + properly configured multi-account containers make this unnecessary?