Open question scoring can definitely be tricky since most quiz plugins don’t provide automated grading for them. Usually, this requires manual review after submissions, or sometimes custom code to extend functionality.
In the meantime, if you’re looking for helpful resources, guides, and tools, I share detailed pages on my site that cover different solutions and workarounds for these types of issues. You may find them useful for managing quizzes or even exploring alternative setups. Feel free to check them out and see if they help with your scoring challenge.