Are the full 8K GPT-4 tokens available on ChatGPT?

I am trying to use GPT-4 at I have GPT-4 access. I assume at this point that means 8K token limit.

I’m trying to get it to help me with a proposal. I feed it text that is exactly 4,653 tokens, and it consistently responds with “The message you submitted was too long, please reload the conversation and submit something shorter.”

I can successfully submit the same text as “user” in the playground OpenAI API (using GPT-4), and I get a response, only that response is limited to 2K tokens. I am hoping to be able to take advantage of the full 8K.

Any suggestions?