Use Teamwork every day and great task management software and absolutely love it and make constant updates to improve the experience. A good place to document everything.
Notifications and customizations are very helpful. The ability to add users from different companies to collaborate in a project is amazing, and for me, it is an edge over other similar PM tools.
I have been using TeamWork for 6 years now, I am very happy with it, and new useful features are always being added, making the tool more and more helpful and efficient.
Our problem was that everyone on our team was using the software differently and projects were getting lost simply because they weren't assigned correctly.
In order for a task to be sent to billing it has to have hours attached. This is a pain if you have no hours but do have materials.
I did not noticed any 2FA warnings when signing from new devices. That's an issue, because projects and tasks may contain some sensitive info.