I've encountered the same in my multiplayer league and figured out which setting causes this bug. Have you set your car setup rules to fixed by any chance? I found that causes it, and changing it to any other setting makes the pre-race strategy appear on the grid. Going to create a bug report for EA about this as this was never an issue with previous F1 games.
edit: here is my report, please me too it so it gets EA's attention: https://answers.ea.com/t5/Technical-Issues-Bug-Reports/Pre-race-strategy-screen-does-not-show-in-25-and-above/m-p/13077486#M11229
