Collaboration not working - freezes up when open project

I am having an issue with team collaboration.

When I create a project and share it with someone using team collaboration, they are unable to edit it. When the other user opens the project, the SqlDBM interface completely freezes up and all menus and buttons stop working. The user then has to close the tab in their browser as nothing works.

The issue is not "lock and edit", because the button can't even be clicked on in the first place.

Both users are able to create and edit their own projects. But this happens every time when using team collaboration.

I have tested this on two different users (one paid and one free), and two different browsers (firefox and chrome). This happens with both existing projects, and newly created projects.