Assistant API parsing wrong file

Hello,
while experimenting with the assistant API ( processing uploaded attachments ) I noticed that sometimes, if for example I’m uploading an image instead of a pdf - but not only - I’m getting back results from another ( seems imaginary ) file that has content totally unrelated with the one I uploaded. Any idea what’s going on?
Thanks!

Seeing similar activity when asking an assistant in gpt-4o to digest a job description and provide back some details - regardless of the file uploaded by the user, the assistant provides hallucinated information, usually related to a Marketing Manager or Project Manager role. Did not significantly change the instructions or calls from gpt-4 turbo to gpt-4o (outside of v2 updates) but 4o seems completely unusable.