See the below screen recording for reference — fairly straightforward bug. On its first attempt, Gemini 3.1 Pro (Preview) was unable to access the attached file. When asked the second time round it seems to have managed. Web Search was turned off for both queries.
Happy to share the thread in full if necessary. Thread ID: 0b4a07c4-347b-4523-b038-6b825f28f91a