I tried to add my credit card to add payment details to use gpt4-vision, however, it requires 5 USD minimum.
You are correct. While you only have free trial credit, your requests are rate limited and some models will be unavailable. Not a bug.
You will indeed need to proceed through to purchasing a prepaid credit to unlock GPT-4. models. Your free trial credit will still be employed first to pay for API usage until it expires or is exhausted.