I have heard that certain classical Shia scholars, such as Shaykh Mufid and Sadooq, denied that the Imams had knowledge of future events and other types of Ilm Ghayb. Is this true?
Bismihi ta'ala
I would like to direct you to something I wrote on my website regarding your important question. Although it is long, but it will hopefully explain this misconception in detail.
http://www.sheikh-alsalami.org.au/2021/12/25/twelver-shiism-and-answerin...
With prayers for your success.