I experienced something similar. My use case is I need to summarize bank statements (sums, averages, etc.). Gemini wouldn't do it, it said too many pages. When I asked the max number of supported pages, it says max is 14 pages. Attempted on both 2.0 flash and 2.0 pro in VertexAI console.
Try with https://aistudio.google.com
Think the page limit is a vertex thing
The only limit in reality is the number of input tokens taken to parse the pdf.
If those tokens + tokens for the rest of your prompt are under the context window limit, you're good.
