Career mode difficulty and session length changes randomly

I started playiing career mode today. I'm playing on long difficulty, full practice sessions. P1 is locked to short as my hard tyres last only 16 laps, then it changes in qualy and in the race.. Also AI difficulty in P1 is different than p3. I set it to 93 but I can outpace them by 2 seconds in p1 and then lose by .3 seconds in p3, then in qualy, Q1 is super difficult and Q3 is super easy, seems to be a bit random. Then in the race the AI seemed ot be running at like 45 difficulty and I was just blasting through everybody. I tried with a new career mode and the same thing happens, what is going on?