Kevin
We're you using the App or PC version? What were your main and advanced strategy settings? Was it raining at the start of the race? Was there any water on the track? During the race where did you make the tyre selection for the next stint, in the strategy tab at the top of the screen (the one that allows you to set both cars) or the individual strategy tabs for each car (the ones at the bottom of the screen).
I ask these questions because I've never experienced this bug in all the time I've played the game and I'm trying to understand if it's random or something to do with the way I play the game.
I had set up everything on a PC. I had no advanced settings because last time it rained it did funny stuff :P I wasn't online for the race though. It was raining already before the race and kept raining until the end.
I simply set up my stints with Intermediate tires and went away. Up until qualifying, no problems, drivers qualified using Inters. When the race started, it defaulted to medium tires and completely different stints, exactly as it would be if I hadn't set up anything before the race. Others in my league had the same thing happen to them. Jose said something got reset before the race so I doubt it has anything to do with play style, though not sure.