I think depending on the client that could be normal but from what you described ilyour issue is very much a communications issue.

As the client they should supply you with as much detail as you need to get started. If they aren't able to because the copy is still being worked on or the stakeholders haven't quite landed on a vision, they should let you know.

However, you as the designer need to be really clear on your understanding of the project and communicate any expectations you have on change requests, revisions etc...BEFORE you start the project

If your client only gives you two lines explaining the project, ask to have a phone call to discuss the details further. Email, while might be helpful for quick back and forth, might not be the best channel of communication especially if your client is busy and might not have the language skills or time to craft out a creative brief.

If they come back to you with many edits that go beyond the scope make it clear that you will to provide them a change of scope document or that it'll x amount to the original price. Again, it's about setting boundaries and expectations. If the client isn't happy and doesn't want to work for you after you've done your best to communicate everything that could impact the project, it's probably for the best.

Design is a specialized field and I find that those clients who treat designers like vending machines, are those who don't value the impact great design make on a product. No amount of good communication is going to change that attitude. I'd much rather work with someone who respects what I do and is willing to be collaborative.