I have created a new project in user account. In this account when i try to assign a billing account , the assignment window is stuck and it is loading for endless time
I had the same issue. I just switch the other project which was billing enable and it worked.
I have the same issue too
It’s because you can’t set billing account more than 2 projects.
Go to the Billing -> Manage billing accounts -> My projects -> and Disable billing in not actual projects if you need this